On Thu, Feb 18, 2010 at 04:27, Nick Rudnick wrote:
I haven't seen anybody mentioning «Joy of Cats» by Adámek, Herrlich & Strecker:
It is available online, and is very well-equipped with thorough explanations, examples, exercises & funny illustrations, I would say best of university lecture style: http://katmat.math.uni-bremen.de/acc/. (Actually, the name of the book is a joke on the set theorists' book «Joy of Set», which again is a joke on «Joy of Sex», which I once found in my parents' bookshelf... ;-))