Well, the way I see it, you have two options, assuming your on windows, MS Paint is perfect if you can figure out how to change the color and such, and the ever so slightly more advanced Graphics Gale is also great. alot of people use programs like Photoshop and Paint Shop Pro. What's wrong with that you ask? It's basicly a million things your never going to use, just alot of extra clutter and harder to get around. So Paint, and Graphics Gale are my recomendations.

Whenever I'm stuck I just kind of blindly play around untill something looks good, then I know I'm on the right track. I don't think I get stuck anymore though. Things become easier the more you do this.

Emulation is definatly the best way to learn. look at SNES or Playstation games, take screenshots, disable layers. You'll get the feel for how everything should look this way. If you don't know what I'm talking about, look it up.