At GISD most admin building and campus conference rooms are reserved in Google Calendar. Many other rooms are reserved in FS Direct (See https://www.georgetownisd.org/Page/18751)
For rooms that can be reserved in Google Calendar follow these steps:
1) Go to Calendar and click the date and time you want to reserve the room, then select More Options
2) On the right side of the screen, click the Rooms tab and then expand the building where you plan to meet.
3) The only rooms that will show up are those that are not already booked at the time you would like to meet. Click the room you would like. It will now show up below in the list of guests for the meeting.
4) Invite your other guests, edit your meeting description, etc. When you save the meeting, the room will be reserved. NOTE: if you change the meeting from "Busy" to "Free" the room could be double booked. It needs to be left as "Busy" if you don't want someone else to be able to book it at the same time.