I recently was re-acquainted with this site and I have to say, I always find new stuff I skimmed over before. There is a wealth of low-level information here, much about the PE file and its makeup. It has one of the best PE file graphics I’ve seen and I really love the x86 oddities post.

The site is called (or run by?) Corkami. Here is the main link.

http://code.google.com/p/corkami/