If you're familiar with C#, Real World Functional Programming: With Examples in F# and C# [1] is an excellent resource for learning how and when to use composition over inheritance.

[1]: http://www.amazon.com/Real-World-Functional-Programming-With...

If you know C# and you want to learn F#, consider reading Real-World Functional Programming: With Examples in C# and F# (http://www.amazon.com/Real-World-Functional-Programming-With...). It's been well-received by C# developers, IMO because it does a great job of explaining the purpose of certain F# features, and how they can be used to simplify some common C# coding patterns.

There's also the excellent F# for Fun and Profit website, which has lots of good F# tutorials: http://fsharpforfunandprofit.com/

As an active contributor to the F# open-source community, I can tell you that there is a lot of effort -- both from Microsoft and the wider community of developers -- to build out the F# ecosystem of tools and libraries. For example, Deedle (https://github.com/BlueMountainCapital/Deedle), a data frame library for F# and C# was released a few days ago; this gives you the kind of data-manipulation functionality as you'd get with Pandas or R. JetBrains even started an open-source project to bring F# support to ReSharper: https://github.com/jetbrains/fsharper

The book by Don Syme (one of the F# creators) is pretty good as it gives an short, yet complete, introduction to the language to people with a functional and .NET background.

http://www.amazon.com/Expert-F-3-0-Apress/dp/1430246502/

I've started functional programming by reading the book about F# by Tomas Petricek. It was really good because it target learning functional programming to someone who have a solid OO background.

http://www.amazon.com/Real-World-Functional-Programming-Toma...