This very same principle applies to anything you want some users to be able to do but not others and is a very basic concept of uaergroups and each groups associated permissions.
While doing what Martok said (had to edit that as special initially called you matron) have a look through the other permissions to see what else you can configure. You can also set permissions on a per forum basis, so some uaergroups can see forums that others can't.