Some Readings would be:

And They Crucified Him

Mark 15:22-25 -- They brought Jesus to the place called Golgotha (which means The Place of the Skull). 23 Then they offered him wine mixed with myrrh, but he did not take it. 24 And they crucified him . . . 25 It was the third hour when they crucified him.

1Cor. 15:1-3 -- Now, brothers, I want to remind you of the gospel I preached to you, which you received and on which you have taken your stand. 2 By this gospel you are saved, if you hold firmly to the word I preached to you. Otherwise, you have believed in vain. 3 For what I received I passed on to you as of first importance: that Christ died for our sins according to the Scriptures.

This is the King of the Jews

John 19:19-22 -- Pilate had a notice prepared and fastened to the cross. It read: JESUS OF NAZARETH, THE KING OF THE JEWS. 20 Many of the Jews read this sign, for the place where Jesus was crucified was near the city, and the sign was written in Aramaic, Latin and Greek. 21 The chief priests of the Jews protested to Pilate, "Do not write `The King of the Jews,' but that this man claimed to be king of the Jews." 22 Pilate answered, "What I have written, I have written."

Rom. 5:6-8 -- You see, at just the right time, when we were still powerless, Christ died for the ungodly. 7 Very rarely will anyone die for a righteous man, though for a good man someone might possibly dare to die. 8 But God demonstrates his own love for us in this: While we were still sinners, Christ died for us.

His First Word on the Cross

Luke 23:33-34 -- When they came to the place called the Skull, there they crucified him, along with the criminals-- one on his right, the other on his left. 34 Jesus said, "Father, forgive them, for they do not know what they are doing."

Rom. 5:9-10 -- Since we have now been justified by his blood, how much more shall we be saved from God's wrath through him! 10 For if, when we were God's enemies, we were reconciled to him through the death of his Son, how much more, having been reconciled, shall we be saved through his life!

Casting Lots for the Seamless Robe

John 19:23-24 -- When the soldiers crucified Jesus, they took his clothes, dividing them into four shares, one for each of them, with the undergarment remaining. This garment was seamless, woven in one piece from top to bottom. 24 "Let's not tear it," they said to one another. "Let's decide by lot who will get it." This happened that the scripture might be fulfilled which said, "They divided my garments among them and cast lots for my clothing." So this is what the soldiers did.

Rom. 3:23-26 -- for all have sinned and fall short of the glory of God, 24 and are justified freely by his grace through the redemption that came by Christ Jesus. 25 God presented him as a sacrifice of atonement, through faith in his blood. He did this to demonstrate his justice, because in his forbearance he had left the sins committed beforehand unpunished-- 26 he did it to demonstrate his justice at the present time, so as to be just and the one who justifies those who have faith in Jesus

Blasphemed and Mocked by All

Matt. 27:39-44 -- Those who passed by hurled insults at him, shaking their heads 40 and saying, "You who are going to destroy the temple and build it in three days, save yourself! Come down from the cross, if you are the Son of God!" 41 In the same way the chief priests, the teachers of the law and the elders mocked him. 42 "He saved others," they said, "but he can't save himself! He's the King of Israel! Let him come down now from the cross, and we will believe in him. 43 He trusts in God. Let God rescue him now if he wants him, for he said, `I am the Son of God.'" 44 In the same way the robbers who were crucified with him also heaped insults on him.

Luke 23:36-37 -- The soldiers also came up and mocked him. They offered him wine vinegar 37 and said, "If you are the king of the Jews, save yourself."

Gal. 3:13 -- Christ redeemed us from the curse of the law by becoming a curse for us, for it is written: "Cursed is everyone who is hung on a tree."

His Second Word

John 19:25-27 -- Near the cross of Jesus stood his mother, his mother's sister, Mary the wife of Clopas, and Mary Magdalene. 26 When Jesus saw his mother there, and the disciple whom he loved standing nearby, he said to his mother, "Dear woman, here is your son," 27 and to the disciple, "Here is your mother." From that time on, this disciple took her into his home.

1Pet. 2:24 -- He himself bore our sins in his body on the tree, so that we might die to sins and live for righteousness; by his wounds you have been healed.

His Third Word

Luke 23:39-43 -- One of the criminals who hung there hurled insults at him: "Aren't you the Christ? Save yourself and us!" 40 But the other criminal rebuked him. "Don't you fear God," he said, "since you are under the same sentence? 41 We are punished justly, for we are getting what our deeds deserve. But this man has done nothing wrong." 42 Then he said, "Jesus, remember me when you come into your kingdom." 43 Jesus answered him, "I tell you the truth, today you will be with me in paradise."

1Pet 3:18 -- For Christ died for sins once for all, the righteous for the unrighteous, to bring you to God.

His Fourth Word

Mark 15:33-36 -- At the sixth hour darkness came over the whole land until the ninth hour. 34 And at the ninth hour Jesus cried out in a loud voice, "Eloi, Eloi, lama sabachthani?"--which means, "My God, my God, why have you forsaken me?" 35 When some of those standing near heard this, they said, "Listen, he's calling Elijah." 36 One man ran, filled a sponge with wine vinegar, put it on a stick, and offered it to Jesus to drink. "Now leave him alone. Let's see if Elijah comes to take him down," he said.

Col. 1:19-23 -- For God was pleased to have all his fullness dwell in him, 20 and through him to reconcile to himself all things, whether things on earth or things in heaven, by making peace through his blood, shed on the cross. 21 Once you were alienated from God and were enemies in your minds because of your evil behaviour. 22 But now he has reconciled you by Christ's physical body through death to present you holy in his sight, without blemish and free from accusation-- 23 if you continue in your faith, established and firm, not moved from the hope held out in the gospel. This is the gospel that you heard and that has been proclaimed to every creature under heaven, and of which I, Paul, have become a servant.

His Fifth and Sixth Words

John 19:28-30 -- Later, knowing that all was now completed, and so that the Scripture would be fulfilled, Jesus said, "I am thirsty." 29 A jar of wine vinegar was there, so they soaked a sponge in it, put the sponge on a stalk of the hyssop plant, and lifted it to Jesus' lips. 30 When he had received the drink, Jesus said, "It is finished."

1John 2:1-2 -- My dear children, I write this to you so that you will not sin. But if anybody does sin, we have one who speaks to the Father in our defence--Jesus Christ, the Righteous One. 2 He is the atoning sacrifice for our sins, and not only for ours but also for the sins of the whole world.

His Seventh Word and His Death

Luke 23:46 -- Jesus called out with a loud voice, "Father, into your hands I commit my spirit." When he had said this, he breathed his last.

Heb. 2:14-15 -- Since the children have flesh and blood, he too shared in their humanity so that by his death he might destroy him who holds the power of death--that is, the devil-- 15 and free those who all their lives were held in slavery by their fear of death.

Col. 2:13 -- When you were dead in your sins and in the uncircumcision of your sinful nature, God made you alive with Christ. He forgave us all our sins, 14 having cancelled the written code, with its regulations, that was against us and that stood opposed to us; he took it away, nailing it to the cross. 15 And having disarmed the powers and authorities, he made a public spectacle of them, triumphing over them by the cross.

The Miraculous Signs

Matt. 27:51-56 -- At that moment the curtain of the temple was torn in two from top to bottom. The earth shook and the rocks split. 52 The tombs broke open and the bodies of many holy people who had died were raised to life. 53 They came out of the tombs, and after Jesus' resurrection they went into the holy city and appeared to many people. 54 When the centurion and those with him who were guarding Jesus saw the earthquake and all that had happened, they were terrified, and exclaimed, "Surely he was the Son of God!" 55 Many women were there, watching from a distance. They had followed Jesus from Galilee to care for his needs. 56 Among them were Mary Magdalene, Mary the mother of James and Joses, and the mother of Zebedee's sons.

Heb. 7:26-27 -- Such a high priest meets our need--one who is holy, blameless, pure, set apart from sinners, exalted above the heavens. 27 Unlike the other high priests, he does not need to offer sacrifices day after day, first for his own sins, and then for the sins of the people. He sacrificed for their sins once for all when he offered himself.

Heb. 9:25-28 -- Nor did he enter heaven to offer himself again and again, the way the high priest enters the Most Holy Place every year with blood that is not his own. 26 Then Christ would have had to suffer many times since the creation of the world. But now he has appeared once for all at the end of the ages to do away with sin by the sacrifice of himself. 27 Just as man is destined to die once, and after that to face judgement, 28 so Christ was sacrificed once to take away the sins of many people; and he will appear a second time, not to bear sin, but to bring salvation to those who are waiting for him.

They Pierce His Side

John 19:31-37 -- Now it was the day of Preparation, and the next day was to be a special Sabbath. Because the Jews did not want the bodies left on the crosses during the Sabbath, they asked Pilate to have the legs broken and the bodies taken down. 32 The soldiers therefore came and broke the legs of the first man who had been crucified with Jesus, and then those of the other. 33 But when they came to Jesus and found that he was already dead, they did not break his legs. 34 Instead, one of the soldiers pierced Jesus' side with a spear, bringing a sudden flow of blood and water. 35 The man who saw it has given testimony, and his testimony is true. He knows that he tells the truth, and he testifies so that you also may believe. 36 These things happened so that the scripture would be fulfilled: "Not one of his bones will be broken," 37 and, as another scripture says, "They will look on the one they have pierced."

Eph. 1:7 -- In him we have redemption through his blood, the forgiveness of sins, in accordance with the riches of God's grace

1Pet. 1:18-19 -- For you know that it was not with perishable things such as silver or gold that you were redeemed from the empty way of life handed down to you from your forefathers, 19 but with the precious blood of Christ, a lamb without blemish or defect.

The Burial

John 19:38-42 -- Later, Joseph of Arimathea asked Pilate for the body of Jesus. Now Joseph was a disciple of Jesus, but secretly because he feared the Jews. With Pilate's permission, he came and took the body away. 39 He was accompanied by Nicodemus, the man who earlier had visited Jesus at night. Nicodemus brought a mixture of myrrh and aloes, about seventy-five pounds. 40 Taking Jesus' body, the two of them wrapped it, with the spices, in strips of linen. This was in accordance with Jewish burial customs. 41 At the place where Jesus was crucified, there was a garden, and in the garden a new tomb, in which no one had ever been laid. 42 Because it was the Jewish day of Preparation and since the tomb was nearby, they laid Jesus there.

Matt. 27:60-66 -- He rolled a big stone in front of the entrance to the tomb and went away. 61 Mary Magdalene and the other Mary were sitting there opposite the tomb. 62 The next day, the one after Preparation Day, the chief priests and the Pharisees went to Pilate. 63 "Sir," they said, "we remember that while he was still alive that deceiver said, `After three days I will rise again.' 64 So give the order for the tomb to be made secure until the third day. Otherwise, his disciples may come and steal the body and tell the people that he has been raised from the dead. This last deception will be worse than the first." 65 "Take a guard," Pilate answered. "Go, make the tomb as secure as you know how." 66 So they went and made the tomb secure by putting a seal on the stone and posting the guard.

Gal. 2:20-21 -- I have been crucified with Christ and I no longer live, but Christ lives in me. The life I live in the body, I live by faith in the Son of God, who loved me and gave himself for me. 21 I do not set aside the grace of God, for if righteousness could be gained through the law, Christ died for nothing!"

Because it's the day that Jesus died on the cross, so it is called good because he did it so all our sins could be forgiven.

Actually He could not have died on Friday because the Bible says He was dead three days and three nights. That would not be possible between Friday and Sunday.

Actually the Jesus says in the Bible that on the third day he will rise, not three days and nights.

additional information comes from "the advent" Catholic encyclopedia:

From the earliest times the Christians always kept every Friday as a day to feast/gather; Friday which marks the anniversary of the Christ's death; came to be called the Great or the Holy or the Good Friday. The origin of the term Good is not clear. Some say it is from "God's Friday" (Gottes Freitag); others maintain that it is from the German Gute Freitag, and not specially English. Sometimes, the day was also called Long Friday by the Anglo-Saxons.

A sin is committed. It is a seirous (mortal) sin if the person is above the age of 14 and does not have a special dispensation, knows that it was a sin to do so, and ate meat anyways. It is a venial sin if it was done by accident or without really understanding this or was of course, not consenting to the act through free will.

In the case of a mortal sin, a confession is needed. In the case of venial sin, a confession is a good idea, but not required. A normal act of contrition and some self-specified penance is needed.
It can happen, it is a sin if the person is 14 years or older and does not have a dispensation. If it was done because one was careless then the sin is still a grave one. Seek a confession in this case.