I found a useful graphic program, that's as easy as MS Paint, but much better. It even lets you download the source code to make your own mods of it. For example theres a mod where you can put your own scripts in it to do things like light effects. Anyways it's called Paint.NET, and it uses the .NET framework, so you will need to install that it you dont have it.
http://www.eecs.wsu.edu/paint.net/