[This is going to be rather long, sorry for that. Yet I would really appreciate your thoughts in this matter.]
I managed to set up a nice drupal community site, and everything seems to be working fine. But the more I think about vocabularies, the more confused I get. I'm just not sure if I'm using vocabularies "right". Meanwhile I even think that there is not really one way to do it "right", but - after looking at different drupal sites - I saw a lot of different approaches, and I'm still not sure which is the best way for my site. (which, fortunately, does not matter too much, since you can always "reorganize" - a big plus for drupal in my eyes.)
I started out creating different vocabularies for the different modules, one for "News" (articles), one for the forums, one for events, one for picture galleries and so on. It seemed the natural thing to do.
But now that we've been online for 3 days, I begin to see backdraws to that strategy. For instance, if I "promote" a forum entry to the front page, the taxonomy-term links to the other forum-entries of that term - but not to the news articles with same or similar topic. Same goes for events, images... etc.
While this is perfectly understandable from the admin's point of view, I'm afraid it will get users confused. But how to prevent it?
I sat down & tried to create a vocabulary structure that fits the needs of all modules I use (except weblink, which will always be slightly different). While this is cool for news, for the book, etc, it would be a real overkill for image galleries... and especially for the forum. I'm afraid that a forum with 30-40 subterms will look deserted however many people write in it.