User:Nathan Larson/Guide

Challenges
I think the hardest thing about wikis is just getting them to a critical mass of activity to where they avoid becoming defunct. (The web is littered with abandoned wikis.) The key is probably putting a pretty face on it and creating an appearance of activity, so that people will be more inclined to contribute. I.e., have a featured article on the Main Page that you rotate frequently, so that it appears as though you have so much content that you only have room on the main page to showcase your very best stuff. Also, have a news section that is updated often. And just for fun, maybe have a "did you know" section to put off-the-wall facts. In other words, basically rip off Wikipedia's model. With any luck, you can get some random contributors showing up out of nowhere who weren't previously associated with your organization.

Another key is differentiating the wiki from other wikis out there. That's important because if there is overlap in content, users may eventually view their work on this project as redundant, and jump ship to contribute primarily to competing wiki(s). Wikipedia, as the biggest and most popular wiki around, could be your prime competitor. Many encyclopedia-like sites have differentiated themselves from Wikipedia, however, by allowing original research or relaxing notability requirements.

Licensing
There is also the issue of licensing. Should your site use GFDL, Creative Commons, or public domain? I recommend the latter, since it's the most flexible. Once you go the GFDL or CC route, there's no going back; your content is shackled by that license until the copyright expires, and any additions people make to licensed pages are also subject to the same license. GFDL's restrictions seem particularly onerous, and Wikipedia is presently trying to figure out how to get out of its GFDL license. The downside to releasing everything into the public domain is that if someone takes your content and posts an improved version elsewhere, you have to ask permission if you want to use their alterations; if your work were released under GFDL or CC, then any alterations would also be free-licensed.

User friendliness
Mediawiki is really powerful and is the one I'm most adept at using, but I have to admit that it's not the most user-friendly software in the world. Certain features, such as a WYSIWYG, may be impossible to implement. You can minimize the non-user-friendliness of it by setting up guides for new users. (e.g. "Click here to upload a new flyer") There are probably already a lot of people who are familiar with Mediawiki markup anyway, since it's one of the most common wiki applications in use today.