I get a lot of questions about what I use to make graphics. So here they are. They are all simple, small, and easy to use.
MSPaint - As long as you use Windows, you should know what this is. I use it for pixel work.
InfranView - I use this mainly for converting between image types (bmp, gif, jpg, and png), and also as a clipboard when I'm Copy and pasting.
Giffy - The easiest transparency maker in the world. Open a gif, click the color you want to be transparent, save the gif. That's all.
Gif2Mng - Graal comes with this program. It changes single frame gifs to pngs, and animated gifs to mng. Simply put the gif in the same folder, open that folder, type "gif2mng <filename.gif>" in the url/folder bar at the top of the screen. And it instantly creates the png/mng for you and puts it in that same folder.
AniMagic - Makes animated gifs. Just copy and paste your frames to the program, you can also set transparencies and frame rates. Search for it on Download.com, I'm not sure what the real website url is.
And that's all. I know it's a lot, but the only ones I really ever use is Paint, Giffy, and InfranView. Those are the ones that anyone should have.