get paint.net or the gimp first
they're both free, so you can try both to see what you like best. once you've got the hang of it, photoshop{,elements} or corel paint shop pro are the next step if you feel you need something shinier
( spacefish bong!, Fri 15 May 2009, 13:25, archived)

You are a friendly man mr. spacefish.

( Undulating Tentacles of Love getting fun down to acceptable levels, Fri 15 May 2009, 13:39, archived)

OFF WITH HIS HEAD!

(likeajackhammer, Fri 15 May 2009, 13:44, archived)