Here are what I think to be the sites with more information than anybody has a right to expect...and probably a lot more than anybody (except me) cares to know.
You could easily spend several hours at the Cardas site. The best also has the best site.
The Audioquest site is almost as good, but not quite.
I could have included Tara Labs and Kimber to round out the top guys in the field, but their sites are not as user friendly and the Cardas and Audioquest will probably keep you busy if you have even the slightest interest in understanding cable.
The last link is a good starter and should probably be read first.
Matthew Bond of Tara has one of the best white papers on cabling if you want to suffer through their site to find it.