Humble Book Bundle: Be a coder - Great collection of books covering Python, R, Erlang, Haskell, Racket, Clojure & more
Humble Bundle is doing another programming books bundle and this one looks really great, especially if you're interested in learning functional programming. It's all books from the publisher No Starch Press, which has become a brand name for easy to digest, humorous programming books and books covering areas that aren't usually well covered.
I haven't read all of the books of course, but I've read Learn you a Haskell for great good, Land of Lisp, Realm of Racket, and I am currently reading Clojure for the Brave and True, and these books I can say I really liked and are well worth having. I really like the No Starch Press formula of making a dry topic like programming fun.
As usual, there are different tiers you can purchase, the more you pay the more books you get with the cheapest tier starting at just $1 and higher tiers including all the books of lower tiers. Personally I think you should get the $8 tier which covers Erlang, Haskell, Python, R, Assembly, Clojure, Lisp and Racket. Or the $15 tier which adds Ruby and JavaScript (specifically ECMAScript 6) to the mix of covered languages, but really all of the must have books (in my humble opinion of course) are in the $8 tier. One caveat, the Python book is aimed at parents who want to teach their kids programming.
Here are the different tiers: