See the MediaWiki guide for basic help about using this kind of Wiki.
WikiPedia, which uses the same software, has a nice tutorial for editing and posting new pages.
In addition, you may want to have a look at the Help:Editing page here, just don't let all the red links scare you!
I honestly don't know what kind of help people expect, so if the links above don't satisfy your needs, please direct your questions to this page or its discussion area, and we'll try our best to answer them. -Captain