Wikis are good if you want everyone to be able to edit everyone's content. Mediawiki doesn't have very good user access controls, but there are some wiki systems that give you more control over who can edit what. Also remember that wikis are for showing the edited articles directly on the web.
A CMS may be better if you want more features added to displaying your content after it has been created. Maybe you want to add discussion forums to your site, or membership options for site viewers. I've used joomla! quite a lot, but it could be overkill for what you're doing.
Also how web literate are your domain experts? If they're experts in, say, knitting you may be better off setting up a system where they create content just in word, and then you upload it to the site.
If you give us more details, maybe someone can help you out a bit more.
The term you are looking for is a "CMS". Good luck.
http://en.wikipedia.org/wiki/List_of_content_management_syst...