The Haskell School of Expression shows you how to make interesting applications in Haskell. Unlike the other Haskell books this one tries to avoid mathematical oriented programs as examples. Instead it gets you writing programs using the haskell graphics and music libraries which are much more interesting. Frivolous things like that can sometimes over-complicate simple ideas which are trying to be conveyed though. Also the first chapter is very ambitious introducting lots of new ideas which are not easy to link together. Lots of proof techniques are used throughout which may be hard to understand at first. On the whole the text is fascinating as it shows what a novel and ideal approach functional programming is for making graphics applications. Very good content, but I'm not sure if it should be your first read if you are new to functional programming.
This book provides an interesting approach to learning Haskell which is designed to keep the learner interested through the use of multimedia. Although I feel that sometimes this can cloud the simple principles being taught.