The computer allows you to make mistakes faster than any other invention, with the possible exception of handguns and tequila.
1.3 Mb download
It is one of the few image manipulating programs that was designed with newer computers (including Vista) in mind. Paint.NET is totally FREE, supports layers, special effects and has lots of useful and powerful tools to keep you happy and busy for a long time.
There is also a very active online community, providing friendly help, tutorials and plugins.
I can't believe they can get so much goodness in such a tiny installation file!
The Status Bar (bottom of the main window) is a great source of tips and hints for whatever tool you happen to be using at the moment. Keep your eye on it while you are learning. It is a terrific resource. There is also an extensive help resource on the Internet, so if you are connected, help is only a click away.