Patterns in Functional Programming
The good news is that Jeremy Gibbons is writing a book on Patterns in Functional Programming. Even better news is that he is blogging about it as he goes along!
Those unfamiliar with the topic may want to begin at the beginning, though I personally just rummaged around. Some may enjoy going to the papers rather than the blog, or even better to the LtU discussions about many of them. Alternatively, I think it might be a great opportunity to ask Jeremy questions using the comments on his blog. I am sure this can be a very productive learning experience, and will surely help the book!