You can not enchant an already enchanted item. To increase the ability of the enchantment you need to level your Enchanting skill. To fully use your high level Enchanting skill you need to use Grand Soul Gems, Black Soul Gems, or Azura's Star/The Black Star.
The grindstone stands for work.
You don't need to buy Skyrim from Steam, but it does need to be linked to your Steam account (by registering the serial code you should have got with the game).
You make it yourself once you reach skill level 90 on Smithing. You need Ebony Ore and Daedra Hearts.
Dawnguard is basically an expansion pack for skyrim. like all expansion packs, it requires the base game to play. So on a PC (and any other gaming device) you need skyrim first and then you can install dawnguard.
No, you only need a gold membership if you want to talk to your friends while playing the game.
Do out of the ordinary things in the game. When you do them you get the skill point. The name will help you with what you need to do. Get Skill points to unlock cheats.
You need to install a mod, user-made content where someone has added them into the game.
There is no in-game recipe for Skooma. You just have to find it ready made if you need it.
The truth is that you do not need skill to play soccer because its a very simple game to learn. It's actually like basketball, it has defenders and everything. But it is true that you do not need skill to play soccer.
No
You will find on corpses you defeat, or in chests or other places daggers. Sometimes people will be selling them too. As you go into the game further you will find more powerful ones. You can use a grindstone to make them more powerful, increase perks in one handed skill to give daggers more attack, or enchant them to give them abilities. If you wish, you can increase your blacksmitting perks so that you can craft with things like ebony or glass, and make a dagger from them which is very powerful.