I've seen waay too many treads titled "how do i do this with paint?" and "is this supposed to happen?" and, "why my program no work!??!" that immediately get locked. Here's the place to ask those questions!
Programs! - these are your tools.
freeware
the GIMP - simple image editing, and some tablet support.
Paint- comes with any PC.
Infran View - image viewer, you can open anything and save it to everything.
Paint.net- pretty decent freeware, but the brush bleeds a lot with a tablet.
The big ones
corel Painter $430 - very intent on realism, it renders brush strokes. lack of filters, 30 day trial.
Photoshop- $650- $1,000. it's got its own verb. plenty of filters, and intuitive brush customization.
Flash - $700, vector/animation software. it's what the stuff in the portal is (usually) made with.
Illustrator- $600, another major vector software. i don't know much about this one.
Keep it to technical questions/bug squashing. I don't know much at all about the artistic side of art, so keep that to the actual forum, just remember to post your picture first! Don't know how to do that? It's that "Browse..." button below where you type. if it won't fit, crop/resize it. Or else.
(also, added a pretty picture to keep this thread 'legal'.)