Also, when viewing the index page of any of the forums/sub-forums (not the main index page), scroll all the way to the bottom. It gives you an icon legend, you can see the assigned Admins/Mods for that particular forum, tells you how many members and how many guests* are in the forum, accesses the thread display tools at your disposable, and shows you your site permissions.

*guests can be unregistered/unique users and/or registered members who logged out from their previous session and haven't logged back in. You would also be surprised at the number of people who join just so that they can view attachments and rarely (if ever) post.