Survey of Web Genres
Peterme points to Kevin Crowston's Reproduced and emergent genres of communication on the World-Wide Web which is -- and I'm not exaggerating here -- design gold. It really is. It relates to work by researchers such as Dillon and Toms on information shape and genre that I summarized in my navigation research paper (.pdf). The argument, put simply, is that if we format information using familiar genres, the familiar information structure of those genres can become more intuitable navigation (intuitive, of course, equals familiar).
What Crowston has done is survey and document all those genres. So the step I describe of "formatting information in familiar genres when possible" becomes easier when we have a list of common genres. Then you just need to figure out which genres your audience recognizes.