A great comprehensive video tutorial from TutCandy. Click the play button and learn how to convert a sketch into digital artwork using Adobe Photoshop and Adobe Illustrator. If you pay attention you may also learn some useful shortcuts.
"In this tutorial we will show you how to go from sketch to vector and maintain that hand-drawn look. We start off cleaning the image in Photoshop, don't freak if you haven't got it, all photo editing software should have very similar functions.
Then take it into illustrator and use the automated live trace tool, which I normally think auto anything does a pretty terrible job but for rough hand-drawn linework it will work just perfectly."