Often I've seen on Chow the EG gullet link to understanding cookware:
However, I just came across this, and the associated links near the top: http://www.centurylife.org/how-to-cho...
This also appears to be a very thorough and knowledgeable set of pages on the different metals, rivets vs. welds, heat transfer, etc. There is a super long page on All Clad history and its different lines, too:
I'm sure many points are debatable, but this sure looks good to me.