This is the best introduction to "Monads" for newbies and imparative mined that I'v ever read! For a long time I was searching for such an excellent text on monads. Ofcourse there are many good text there. But all of them are about mathematics and how clever the monads are. After all most of them are useless for a practical approach. Take a look at this http://sigfpe.blogspot.com/2006/08/you-could-have-invented-monads-and.html !! Have a good time with it!!