I use photoshop for everything but honestly its time consuming to learn and it won't be an overnight type of thing.
What he said. I use photoshop a lot and it is very time consuming to learn how to use it properly. One tip I can give you, is get a copy of it, and fool around editing home made pictures. Or to draw a sketch, and color it using photoshop.
Also here are a few links that might help you: http://sixrevisions.com/graphics-des...ith-photoshop/