Stickwelder
Welcome to the Forum!
Since your questions are pretty general in nature it might be best to give you a whole bunch of general information and you can sort through it for what applies best to you.
Go here
http://millerwelds.com/resources/improving-your-skills/tig/I like the "Tig Handbook" on this site for basic information
There are videos and lots of other good free stuff too.
When you read all that and still have more questions or if anything doesn't make sense... Just post em here..