Haskell Programming by Christopher Allen
The PDF covers the following topics related to Haskell Programming : All You Need is Lambda, Hello, Haskell!, Strings, Basic datatypes, Types, Typeclasses, More functional patterns, Recursion, Lists, Folding lists, Algebraic datatypes, Signaling adversity, Testing, Monoid, Semigroup, Functor, Applicative, Monad, Applying structure, Foldable, Traversable, Reader, State, Parser combinators, Composing types, Monad transformers, Non-strictness, Basic libraries, IO.
Author(s): Christopher Allen, Julie Moronuki
1076 Pages 
This note explains The concurrent package, The data package, The lang package, The net package, The num package, The posix package, The text package, The util package, and the Win32 package.
Author(s): The GHC Team
49 Pages
This note describes the basics of Haskell including installation and variables and gradually progressing to more advanced concepts such as monads, type classes, performance, and specialized tasks like graphical user interfaces and working with databases. The document also includes information on libraries, testing, packaging, and the Foreign Function Interface.
Author(s): en.wikibooks.org
683 Pages
