Create a room mailbox for it. Then you can set who gets emailed to approve the requests.
It's all documented here on technet - that page walks you through the steps below:
- Create a new mailbox, choosing room for the mailbox type
- Set a delegate for the mailbox - this is the person who has to approve the requests
- Configure automatic booking for the mailbox
To make people use meeting requests, you would want BookInPolicy set to nobody, RequestInPolicy and RequestOutofPolicy for everyone - this will send a request to the delegate to approve it. You can also give certain people full permissions to the calendar or mailbox to let them edit it without going through the delegate or using a meeting request.