You can find useful information about various settings releated to Reservation system in this article. To open the settings page, navigate to Admin zone -> Main menu -> Global settings -> tab Reservation system. 

Reservation system settings

Image: Reservation system settings
Reservation system

Enable Reservations module - you can enable or disable Reservation system by clicking this checkbox

Reservation system object groups definition - you can define your own object groups for your reservation system by clicking the classifier icon. A new window will appear where you can add or remove items.

Creating new group of objects

Image: Creating new group of objects