Tom's Hardware - How To Customize Your PC Case & Achieve Professional Results

Great article with good instructions on some mods including fitting a window in your case which might he a bit tricky if you have never done it before....

http://www.tomshardware.com/howto/02q3/020724/index.html

This is a good article. I read most of it earlier today. Really opened my eyes to the world of the possibilities of painting my case.