Animation Source Forums

Yes, do not confuse the sites which USE phpBB (or other kind of forum softwares) and allow you to make a forum in three clicks, with the forum software itself.
If you already have a host, do what Togo said. (it's the way I'm doing it) Otherwise, either consider paying for being hosted (if you wish to add a real site with it), or just keep using an automated site like proboards or all the others.
The big advantage of hosting your forum yourself is that you can configure everything like you wish, and even modify the forum code.
The big advantage of using an automated site is that it's much easier to create it...

So how do I find a host?

I dunno about making a website, i wouldn't even know where to begin with that.