I strongly recommend the second edition, which is an extensively revised, extended and mostly improved revision of the first edition. I have read both editions. The first edition has an example on solving the 8 queens problem with backtracking, unfortunately this example was dropped in the second edition. The second edition is my favourite book on Haskell.

The examples are from mathematics, including proof by induction. The material on deriving programs from their specifications by Bird in the second edition is awesome, I love this book. If you can handle examples from maths, this book is superb.

I think this book is also a great introductory text on Haskell, however I found that as soon as I tried writing Haskell programs that I often had to read material from other tutorials, and kept having to refer to Real World Haskell.

Another great text on mathematics and logic, with examples using Haskell that helps to understand the maths, is the Haskell Road to Logic, Maths and Programming. Bird's text goes much deeper on Haskell programming.