The below is a tiny fraction of what is available online; for more, start at haskell.org.
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
Dartmouth Problem Solving with Computer Science
Princeton Programming Languages