Stewart Mader of Wikipatterns, Wikis in Education and other great feats of wikitivity has started a [1] 21 days series explaining wikis and how they can be used. So far:
Day 1 Growing wiki support from grassroots
Day 2 Explaining differences between wikis and email
Day 3 Conditions for successful wikis, wikipedia isn’t only way

When I was creating a variety of wikis last year and advising others on getting going, we used the wikipatterns to help promote discussion beyond ok - we’ve got started, now what happens. Its easy to fall into anti-patterns even unintentionally whilst you are getting familiar with contributing in a public editable space and the patterns provide great examples to assist with wiki community building.