I read "Categories for the working mathematican" by Saunders Mac Lane and "The Typeclassopedia" by Brent Yorgey before I really understood monads.<p>If i just waited for this, it could have spared me all this reading ;-)
Always loving bonus500's style. It's striking, though, how often guides to monads crop up on sites like HN. No matter how many introductions or "monads for idiots" type articles get written, it seems they're conceptually difficult enough to always need more ;-)
Though I definitely didn't finish reading this, I couldn't help but remember Why's Poignant Guide to Ruby (<a href="http://mislav.uniqpath.com/poignant-guide/" rel="nofollow">http://mislav.uniqpath.com/poignant-guide/</a>) - this is probably the prettiest Haskell learning resource writeup I've seen up to date :)