Where to find ATX case Specifications?

I'm thinking of building my own computer case out of plexiglass, and I was wondering is there some place online where I can find the specifications for everything, or should I just take one of my own cases and try to measure everything out.

 

Might try http://www.formfactors.org/default.asp

 

Yea, formfactors.org has all of it.

Thats gonna be a pretty good project...