Related KBs:
Outlook - Sharing Your Calendar
Outlook - Checking Storage Space
Outlook - Configuring Out of Office Replies
Outlook - Attachment and Recipient Limits
Outlook - Creating Space
Outlook - Forward an Email as an Attachment
Outlook - Prevent .ost File Errors

1. Remove any existing favorites for the Public Folder calendar (if present).

2. Open the Room calendar from the directory.

3.  Highlight your selection of rooms and select the "Rooms ->" key to add them.  Once you're finished, select "OK."

4. When creating a calendar item within your own calendar, you can also invite the room as an attendee.  Click New Appointment to view the Scheduling Assistant option.