If you have Windows on your computer then you may not need any programs at all to install mods into minecraft; just open %appdata %\.minecraft\bin and rename minecraft.jar to minecraft.zip, add whatever it is you want to add, then rename it back to minecraft.jar.
I recommend you use WinRAR though. Wherever minecraft.jar is on your computer (I have Windows, so mine is in %appdata %\.minecraft\bin), open it with WinRAR and then you can drag files into it. Most mods come with a readme file that tells you how to install it, or instructions on a website. You will usually need to delete a folder inside minecraft.jar named META-INF.
Don't leave the space before the second % sign.
Remember to back up your minecraft.jar before you try and mod it!
NO!
You don't need a CD for mods. You don't need a CD for Minecraft at all.
any will load mods onto minecraft but the better operating system the more mods you can have
No, you just get them for free
Lots of mods do not need forge, big ones such as: OptiFine Too many items and Better Sprint (all i know of)
To get mod packs you must go to the forums for minecraft. There should be a forum that is for mods and you can find all the mods there. The first mod that you will need for minecraft would be the ModLoader, which is used to load all the mods that you will acquire.
You NEED to have downloaded minecraft to use mods. There are hundreds of mod installation tutorials for all of the most popular mods on YouTube!
No, only when you download them the first time.
no, but to get alot of mod you need to have modloader installed on the game.
you need the pc version on the computer
Mods can usually be downloaded from where they are publishedSome mods come with an installer to install the modFor other mods, you need to install them manually by opening the zip file they are in and copying the contents to the minecraft.jar file found in the bin folder of the .minecraft directory
No it might be that you have an out dated mod that crashes to game or that you do not have something like modloader (which you need for most mods). Also when downloading mods make sure they are for your current version of minecraft or it will defiantly crash.