Help with things you need to know for building.
First off most major building is handled by the staff, with Derpy in charge of "the grid." New rooms can be added to the grip with permission. Speak with Derpy with your idea and she'll decide if suitable and work with you to where it should be. You can also make a "personal" room or two. That's a private room that's not attached to the grid and can only be gotten to by teleporting or a personal link.