To use haskell-mode in Emacs, add the following lines to your ~/.emacs:

(add-to-list 'load-path "%%PREFIX%%/share/emacs/site-lisp/haskell-mode/")
(require 'haskell-mode-autoloads)

Add the following lines according to which modules you want to use:

(add-hook 'haskell-mode-hook 'turn-on-haskell-doc-mode)
(add-hook 'haskell-mode-hook 'turn-on-haskell-indentation)
(add-hook 'haskell-mode-hook 'turn-on-haskell-indent)
(autoload 'turn-on-haskell-indent "hindent" "Indentation mode for Haskell" t)
(add-hook 'haskell-mode-hook 'font-lock-mode)

Note that the three indentation modules are mutually exclusive - add at
most one.