I'm late to this discussion and therefore I don't know if this has been discussed previously but...
I'm a software developer for an internet portal and in this thread 2 things struck me:
1 - You will have a problem structuring your data in a hierarchical manner. Newbies have to think and organize their minds the same way as you.
2 - You seem to want a list of links to existing threads and not a whole re-write of threads in a structured documents.
Taking these into account, maybe what you want is a Tags service: basically a bookmark storage where you associate keywords with the link. Only the meaningful keywords to that thread should be used reducing the problem of too many hits on a search. The most famous service online currently is Delicious (
http://del.icio.us/ ), even though they hit too hard on the social-interaction-crack-pipe-thingy.
It might be simplifying things a bit, but i use a similar system (my employer's home-brewed project) and it helps a LOT to manage/maintain a database of knowledge based on links.