Tools

Don't install or try to use ghc-mod if you're a beginner

It's a bit fragile, more than a bit slow, and it's not worth the grief.

Emacs
- Install haskell-mode
- Install flycheck
- Enable and configure Haskell, this can be just (require 'haskell) if you don't care about anything else.
- Enable flycheck
- Symlink Stack to /usr/bin or otherwise make sure flycheck can find it
- dunzo.
For Vim, we recommend Stephen Diehl's instructions, though we'd recommend not bothering with ghc-mod if possible.
Sublime Text
Atom
IntelliJ
Notepad++ has basic Haskell support built in.
gedit has basic Haskell support built in.