[tommikaikkonen]

I haven't read the book OP linked, but I've been going through Haskell Programming from First Principles for the last 6 weeks or so and it's been fantastic. The price tag is well worth it in terms of frustration and time saved. I'm about two thirds done.

I really like that it builds up from the basics, starting from lambda calculus, and is also very complete in explaining every concept. I don't feel like anything is left unexplained. This is important, because coming from dynamically typed imperative languages, a lot of concepts in Haskell are so alien that you feel like you're learning programming all over again.

The exercises set it apart from other resources. They're plentiful, start simple, but quickly increase in difficulty. A lot of times I thought I had a concept mastered until the exercises presented gaps in my knowledge -- which made me learn the concept that much better.

The completeness means it's a long book (currently 1233 pages). You'll probably need a healthy dose of existing motivation to learn Haskell to get through it.

[mrslave]

+1 for Allen & Moronuki. Long. Well written. Won't repeat what's already been said.