Setting up as a freelance web designer?

Well I cant tell you what I make =)
Some months are good, some are bad. Some projects you overprice, some you get screwed on.
If I went out on my own I believe I could make make more than what I do at my day job. But then I'd have no benefits, steady pay, etc.
And I quote the project, not hourly.

But in order to quote, I'm guessing you do an estimate of hours to completion + testing and such. Any ballpark for the hourly rate? BTW, I'm 12 months out of college, thats why I don't know this stuff I appreciate the replies too