I found the official manual, but there are things it leaves out. Things like...

-What is the difference between Defending and Guarding, and how do they work?
-What does it mean to click that "favored" box on a spell?
-What exactly is the difference between getting the trap disable in the gold area vs getting it in the metal but not gold area vs not hitting any metal? Doesn't seem to have a cut and dry effect.

Anyone know of a wiki or something that actually explains that sort of stuff?

I finally found something decent here:

http://chazzle.tripod.com/tips.html

There is more information on items here:

https://www.tapatalk.com/groups/thecommonroom/my-ultimate-items-database-hoping-it-ll-work-t1085.html

But I still can't find anything explaining how much damage different types of armor absorb. It's a complete mystery.