- default content
- best practices
The initial content of your wiki is important. If people find some useful, relevant content on their first visit they are more likely to see the point of the wiki, to visit again, to make edits, etc. Don't expect new wiki users to create a lot of content from scratch, or to do a lot of content cleanup; they'll get fatigued. Keep the signal to noise ratio fairly high - don't let the useful content be obscured by unhelpful boilerplate, stale wiki docs or junk pages.
A good set of shared policies and social conventions are what make wiki fly. ZopeWiki:ZopeWikiPolicies has some ideas. See also ManagingContentNotes? and BestPractices on WikiWikiWeb, WikiPedia, CommunityWiki?, http://www.possibility.com/epowiki/Wiki.jsp?page=GettingYourWikiAdopted and elsewhere.
An important policy issue for a public wiki is what license the content falls under and who owns the copyright. It's prudent to think about these things and publish a clear policy at the beginning. GNUFreeDocumentationLicense? and CreativeCommons? are two popular content license choices. Look at WikiPedia for an example.
The choice of which page type(s) to offer is an important one for your wiki's success. By default all available page types are offered. You may want to restrict or remove this choice to best suit your users' present needs. See configuring.
DTML in wiki pages
Whether to allow DTML in your zwiki is another important choice. While useful for creative power users, it has security implications and so is off by default. See configuring for more.
Zwiki's page rating feature may be a way to increase the liveness and quality of a wiki, if you can get people to use it a lot. More enhancement is needed. The WikiStats DTML page may be useful for getting an overview of how people are rating things.
Next is server management.