Come up with some kind of style guide, and teach others how to style stuff. When I was in charge of a corporate wiki, all of the other developers would just write crummy prose that was barely formatted, and looked terrible.
Keep away from things that require discussion. I tried shoehorn in a book review section, but it was too difficult to have others comment on things.
Examples of in house libraries are good. And/or "storyboards" walking a user through a process when MethodX is called.
