There's a problem with this, Scream.
The best way to aid newbies is to shut down as many bell/whistle features, remove as many icons, gremlins, buttons, and otherwise generally de-clutter the interface as much as possible. You guys are too close to it, you don't see how crammed and confusing it's all getting (thru the eyes of newbies).
But given that, the one-help-forum-serves-all approach doesn't work, because it will refer frequently to buttons, features, etc, which a given user might not see in his forum. Thus INCREASING confusion.
So these two solutions are essentially at odds. The central help forum is good for NON-newbie forums that have everything turned on. The webmaster would essentially send terrified newbies there for aid and comfort.
But a site that's extra newbie-concerned (and has weeded out features/buttons) will create as much confusion as it dispels by sending them there.
JIM