During the CPSquare conference on Web 2.0 and Communities of Practice, someone referenced Barn Raising as a means for the initial build-out on a wiki. Here's one definition of Barn Raising from the Meatball Wiki:
BarnRaising occurs when a community actively decides to come to the same place at the same time to help achieve some specific goal. The goal may be of direct interest to a subset of the community, such as raising a new barn for an individual CommunityMember, or it may be a SuperordinateGoal, of interest to the entire community, such as a new school.
What a nice way to think about building a community-needed structure and content. In the case of a wiki, the technology makes it relatively easy to build work in unison to build out a wide array of information for the good of the community. And because of the way wikis work, you can have ten or fifty people working together on pages within the wiki. Certainly, there has to be agreement on which areas of the wiki people are working, but the total build-out could be greatly speeded in a barn raising. The other advantage of doing this together is that some of the "I don't know how" aspects can be ironed out through the community interaction.
I get the impression that technology still gets in the way of community building for primarily-online communities. All community / community of practice technology comes with lots of features out of the box, and these settings are generally under control of the organization that installs the software or the person who sets up the online space. These features / settings exist for wikis too, of course. But in general, this stuff shouldn't get in the way of the community. The community is much more interested in building and continuing its shared interest around whatever topic they formed.
Have a barn raising for your community!
Update: Andy Roberts was the source of this thought, and he posted it to his Distributed Action Research blog, Barn Raising.