F# Journal
I came across a great resource on F# a few weeks back - it's a technical journal and is released on a monthly basis (although sometimes there are more than one per month).
Some of the stuff that Jon Harrop writes about (author of F# Journal) is really interesting. Most of what I have read to date I have never seen elsewhere - but the beauty of the F# Journal is that it clearly explains constructs within the F# language using really great examples.
To date some of my most favorite issues of the F# Journal include how to exploit tail recursion (great read!), pattern matching, and recently an issue on the Fourier transform.
If you are into F#, or looking at getting into F# then I highly recommend subscribing to the F# Journal!
...also I'm keeping an eye out for Jon's F# for Visualization book - this should be really good!