A few books that helped me: * Real-World Functional Programming - With Examples in F# and C# by Thomas Petricek This helped me a lot because I'd been working

A few books that helped me: * Real-World Functional Programming - With Examples in F# and C# by Thomas Petricek This helped me a lot because I'd been working solidly with C# for 8 years leading up to it (C++ before, and C before that), so I was very much in C mode. It presents reasons for the functional approach and shows side-by-side C# and F# examples of the various topics covered. It also takes a more practical approach, rather than 'yet another fibonacci example' which you'll see on lots of functional programming tutorials. * Programming in Haskell by Graham Hutton Basically a text-book on learning Haskell, but covers a lot of fundamentalist functional thinking. * Pearls of Functional Algorithm Design Once you have the basics of functional programming knocked then go for this. It teaches you how to think about reducing problems.