Based on EdgeCase's fantastic Ruby koans, the goal of the F# koans is to teach you F# through testing.
When you first run the koans, you'll be presented with a runtime error and a stack trace indicating where the error occured. Your goal is to make the error go away. As you fix each error, you should learn something about the F# language and functional programming in general.
Your journey towards F# enlightenment starts in the AboutAsserts.fs file. These koans will be very simple, so don't overthink them! As you progress through more koans, more and more F# syntax will be introduced which will allow you to solve more complicated problems and use more advanced techniques.
The F# Koans are currently target Visual Studio 2010. The koans should also work with Visual Studio 2008, comand line Mono, and monodevelop. Instructions for those configurations are still //TODO for the time being.
After installing the Powerpack, open the Visual Studio project, right click on the "FSharpKoans" project in the solution explorer and select "Set as StartUp Project".
You'll want to turn off User-unhandled Exceptions. Go to Debug|Exceptions and uncheck the User-unhandled box from the Common Language Runtime Exceptions item.
You can now run the Koans by selecting Debug|Start Debugging (defaults to f5).