How can I get my forum catorgries to split like http://www.vbulletin.org/forum/

[dismas]

So you are asking how to split it like what the tabs at the top of the page do.

From the responses that I've read (still can't find the relevant threads other than the one I posted) you basically create the new forums, set their display order to 0, then create links to them from your main forum page. They won't display on the main forum page since their display order is zero but if a user is directed right to them, via the links, then they will show with their sub forums.