Learning Haskell through Category Theory, and Adventuring in Category Land: Like Flatterland, Only About Categories « Benjamin L. Russell’s Adventures in Programming Language Theory Wonderland
http://dekudekuplex.wordpress.com/2009/01/16/learning-haskell-through-category-theory-and-adventuring-in-category-land-like-flatterland-only-about-categories/

, I hadn’t found an appropriate publication on category theory that addressed the subject at the proper pace,

Arrow, Structures and Functors