If you want to try your hand at wikiing (is that a word?) there are some free wiki sites out there that are good for getting started and trying out the technology. Peanut butter wiki is an example that I have found easy to use. I'm thinking of developing a hands-on workshop for library staff to introduce them to wikis, and pbwiki seems a good candidate. -- Peanut butter wiki is currently offering to double the free space if users write about the service, and I'm hoping to do just that as I think it would come in handy if I get a few people to attend a workshop.
Seedwiki is another, it has more features and is a little more complex to use as you would expect. It does offer blogs within the wikis.
Both of these have a free level of service that can be increased by upgrading to paid accounts.