Here are some popular, functional pixel art editors:
- Grafx2 - Inspired by Deluxe Paint
- Aseprite - In active development; has the RotSprite algorithm included.
- Graphics Gale - Quite popular
- PyxelEdit - Has some convient tools like a color ramp picker and a tile editor
All of these are reasonably priced (or free) but I've switched from Gale to Aseprite, and I think that Aseprite will only be getting better now that its author is able to work on it full-time. He also frequents the google discussion group that is set up for the project, and he is quite open to suggestions. You can buy the binary + updates for $10, or you can compile it by yourself for free (which you'll need to do anyway if you run Linux).
If you're just starting out, here are some helpful tutorials:
http://www.pixeljoint.com/forum/forum_p ... ?TID=11299http://www.pixel.schlet.net/Also, looking at art from experienced pixel artists is good:
http://www.pixeljoint.com/p/6741.htm This guy is one of the best out there. What's most impressive is how he uses a fairly limited palette and large areas of solid colors while still creating a mesmerizing piece.
The 8-bit-style micro-sprites don't take too much formal artistic talent, but making a good color-ramp selection before you begin to draw is very important. I'd recommend that you try not to over-saturate your colors, and that you try to use as few colors to make the piece look good. Avoiding things like banding, bad-anti aliasing, jagged lines, and over-dithering are things to watch out for if you haven't done much pixeling.
Have fun!