The below is a tiny fraction of what is available online; for more, start at haskell.org.
Cheat Sheet
Editor Plugins
Books
Real World Haskell by Bryan O’ Sullivan, John Goerzen, and Don Stewart
The Haskell School of Expression by Paul Hudak
Programming in Haskell by Graham Hutton
Learn You a Haskell by Miran Lipovača
Fancy Types and Verification
Courses
- UPenn Advanced Programming
- Stanford Programming Languages
- Princeton Programming Languages
Miscellaneous
API Search Engine: Hoogle