I just post my videos on Youtube, (Duh!) here at BiM, The Brickfilmer's Guild, and that's about it.
No Facebook page, no website, no Twitter page, no blog. I hear it ain't hardly worth posting a brickfilm on Eurobricks, (Or Rebrick) as both only get about 100 views and rarely any comments, but I can't think of any other places at the moment.
But there's a reason I don't have that many subs, so don't follow my example if you want fame and fortune.
Really, if your animations are good, and you release something on a regular basis, (Which is more my problem) then people will find you and you'll get an audience. BrotherhoodWorkshop is a great example of that.
For promoting them on this site, depending on the film length, I post at least once in the "Frame from your upcoming film" thread, and usually once in the "Sets and props thread." I've also done a poster or two in the respective thread.
I also try to promote stuff via my sig, since it's hard for people to miss it when it's in front of their face all the time.
Setting up your own forum is probably not going to help that much, as people won't find out about the forum until they see your videos elsewhere. It'll probably be better to use that time and effort on other, more established, forms of promotion.