* [Haskell wikibook: Understanding monads](http://en.wikibooks.org/wiki/Haskell/Understanding_monads)
* [Haskell wikibook: Monad Transformers](http://en.wikibooks.org/wiki/Haskell/Monad_transformers)
+* [A State Monad Tutorial](http://strabismicgobbledygook.wordpress.com/2010/03/06/a-state-monad-tutorial/)
* [You Could Have Invented Monads! (And Maybe You Already Have.)](http://blog.sigfpe.com/2006/08/you-could-have-invented-monads-and.html)
* Yet Another Monad Tutorial: [part 1](http://mvanier.livejournal.com/3917.html) [part 2](http://mvanier.livejournal.com/4305.html)
* [Monads for the Working Haskell Programmer -- a short tutorial](http://www.engr.mun.ca/~theo/Misc/haskell_and_monads.htm)