For everything you ever wanted to know about Wikis but were afraid then visit the Help page at Wikipedia.com. It contains everything you will need to know about how Wikis work, how to edit them and more.
Wikipedia runs on the same basic software so most of what works there, will work here. Wikipedia uses alot of custom made extensions for their site so not everything functions the same.
If you have any questions or problems then drop a line on the discussion page and hopefully someone will be able to help you.