According to Wikipedia, the world largest wiki site:
A Wiki ([ˈwiː.kiː] <wee-kee> or [ˈwɪ.kiː] <wick-ey>) is a type of website that allows users to add, remove, or otherwise edit and change most content very quickly and easily.
So basically, you do know how to use a wiki— you just didn't know it was called that. At the bottom right corner of every screen, there is an option called edit. All you have to do is press that button and you can edit the page you are on. You can even add pictures and videos if you want.
Since a lot of people will be using this site, please respect their entries and don't delete them unless the entry is vulgar, offensive, or just plain mean. Similarly, don't post info that is vulgar, offensive or just plain mean either.
If you have any questions, email me (Larissa) and I'll try to help. I'm pretty new to the whole wiki thing myself, so the site will look better with time, hopefully.