You can help us create a better wiki by reading this wiki, and editing it.
If you haven't edited a wiki before you might be bit worried that you'll break it. Don't worry about that, we have all sorts of ways of fixing things. Bear in mind that articles don't 'belong' to the original editor, feel free to modify them, in a helpful fashion. Here's a guide to the formatting commands for the articles.
Even just creating a blank page about something you don't understand can be a help, we don't know what you want to see!
If you've written a worksheet that you are proud of why not post it on the Examples
Even better, if you are a new user, why not write a tutorial