The itT wiki is structured as a tree from the main page, but you're not actually browsing the entire wiki. It's possible to have completely disjoint sections that you can't get to through the main page (though I'd hope we don't ). It's actually kind of like the www that way...

In the absence of such a structure, or to check for disjoint webs, you can go to http://wiki.maemo.org/Special:Allpages to see a list of all pages, anyway. Or click "Random page" until you find something interesting.