TITLE: Encyclopedia of categories
QUESTION [8 upvotes]: Is there a digest of the most widely used categories with their basic properties mentioned? So I could, say, learn from it in a couple of minutes that the category with totally ordered sets as objects and monotonic functions as morphisms hasn't got coproducts (unless for some specific cases).

REPLY [2 votes]: The Joy of Cats contains, as an appendix, a substantial table of some commonly used categories, with references to some of their properties in the text.