Expert F# (Expert's Voice in .Net) by Don Syme, Adam Granicz, and Antonio Cisternino

F# for Scientists by Jon Harrop

Foundations of F# (Expert's Voice in .Net) by Robert Pickering

Real World Functional Programming: With Examples in F# and C#by Tomas Petricek and Jon Skeet

Beginning F# by Robert Pickering

Programming F# by Chris Smith