community guy's got a ton of info on:
Okay, even if i don't like the UGC lingo, the tips in the post are worth a read for those establishing or running moderated communities--or any kind for that matter. Jake points to a whitepaper that goes into detail: Six Techniques for Safer User Generated Content (UGC) Campaigns, focusing on six key, and often under appreciated techniques. I like the tip to enlist users of a community in moderating it.
4. Enlist your users – most site users want a positive experience. Given the opportunity, many of them will help to protect the safety and quality of a project. Enlisting users can not only help moderators, but can engage users in the site itself. Make sure to develop tools and processes that make it easy and rewarding for "good" behaviors to help protect against the "bad" behaviors.
As the community lives a hopefully long and healthy life, the natural evolution is for the participants to define levels of moderation, and to ignore or oust the assholes, to create and enforce what's acceptable and what gets you shot behind the barn.
(if only!) ;-)