As a rule, haskell is not served through the Apache module. You either configure the cgi or fcgi executable, and then use apache, nginix, etc. to invoke this, or use a framework like snap or happstack, which provides its own server. Then you don't need apache, nginix or anything else unless you want to use it as a proxy server (for example, to provide https).
For help, see the web category on the Haskell Wiki: http://www.haskell.org/haskellwiki/Web
Edit: to run hsp, the hsp-cgi package works: http://hackage.haskell.org/package/hsp-cgi
hsp ( cgi , ..), happstack - , , hsp, .