We use Zellr which is an online cloud based booking system.

Here you create an account and login.  This will then give you access to the Zellr platform where you can select your rental period and which rack you would like.  You can then create your barcodes for the items you would like to sell by typing in the description, price and size etc.  When your rental period begins you will be able to login to Zellr online or use the App to track how your sales are going in real time.