Brian, there are three ways (AFAIK) to set up a conference room that automatically accepts meeting invitations. One is to set up a PC that is logged in as the room and set to automatically accept meeting invitations sent to it. Most people don't use that method because of the hardware it requires.
The second way is to run the autoaccept script. The advantage is that you don't have to remember to invite the room as a resource; the disadvantage is that you don't find out immediately whether the room accepted.
The third way is called direct booking. You have to invite the room as a resource or it doesn't work. If you search the Knowledge Base for that phrase, you'll find articles on it.