Hello Ben; welcome to GPWiki
There are many ways you can help out, if you're interested. Take a look at our "Pages Wanted" list:
Is there anything there you feel qualified to tackle? If so, please write a tutorial and link it from the appropriate tutorial listing page!
Or, you can always help by cleaning things up and making things more navigable (ie. Adding category tags to pages, creating templates where needed, etc.)
If you're in doubt about whether or not something needs to be done, just ask! Everyone here will be happy to give you advice, I'm sure