If you are running PowWow version 3.6 (or later... I've been on pw leave over the summer) you can stop reading now. As of ver. 3.6 the ability to host community has gone into the commercialized zone, that is, you have to pay for it.

If you have an earlier version of PowWow and want to host a community, this is where you do it. As far as I know this is still possible.

The Graphical Beginner's Guide to PowWow