You can start a wiki for free on a site called Wikia. If it looks like there's enough interest in this, we can look at migrating it to a dedicated MediaWiki install on our server later, though I suspect the history side of things wouldn't get all that much interest. Perhaps if the wiki also served as a help resource...? (Although, we have the tutorials board for that...)
Anyway, this isn't a project I'm willing to take on at the moment, but if anyone else is, I don't mind helping out in the form of answering questions about NL's history / etc.