Real World Haskell[0] is the best freely available resource imho. If some concepts remain unclear, Learn You a Haskell[1] is a good complement, though it doesn

Real World Haskell[0] is the best freely available resource imho. If some concepts remain unclear, Learn You a Haskell[1] is a good complement, though it doesn't go as deep as Real World Haskell. For example there is no coverage of monad transformers, which is a pity. Typeclassopedia[2] is a great overview of common category-theoretic abstractions used in Haskell programs. [0] http://book.realworldhaskell.org/read/ http://book.realworldhaskell.org/read/ [1] http://learnyouahaskell.com/chapters http://learnyouahaskell.com/chapters [2] https://wiki.haskell.org/Typeclassopedia https://wiki.haskell.org/Typeclassopedia