Wiki

I have set up a pbwiki. The user interface is simpler than media wiki, a bit like blogger really.
There is, of course a commercial version, so the freebie version is limited.
You also get daily emails from them with tips, a seven things of wikis.
PBwiki Quick Start -- Day 3 of 7 - Engage your class

http://cdulibrary.pbwiki.com/