For general graphics development, if you're a cheapass, go with GIMP. Even if you're not a cheapass, go with GIMP - it does pretty much everything Photoshop can do, and has room for more. Also it's completely free. Only downside? GTK+ on Windows is pretty terrible. Even so, it manages quite nicely.
For SPRITING or something, even though I am not a spriter I would probably suggest MS Paint. It's pretty simple, it's RIGHT THERE IN FRONT OF YOU, and most of the spriters I know prefer it.