do you have dbpro or classic, if you have pro you can use create animated sprite. when you use that all the frames are in the same image divided equally. But if you have classic, youll just have to change the image you use for the sprite, i guess.
and for software, mspaint is fine, not the best but it will do, unless you want to spend like $500 for adobe photoshop 7, there was a pretty good paint program that was free, i cant remember what it was called write now though.
edit:yeah, i remember now, its ccalled gimp, get it at
http://www.gimp.org