If you need to setup different locations for your business, just go to Your Business > Overview. On the right-hand side, click on the link next to the Locations heading.
You'll be taken to a page detailing all registered locations for your business. If you would like to add a new one, click on the blue button "Add a new location". Enter the necessary information and click on the blue button on the bottom.
If you need to add departments to the new location, click on the blue button "Manage Departments" and add all the departments you need. Just fill in the name and the accounting code of each department.
These departments will be used when reconciling invoices. It's important to setup these departments correctly if orders and deliveries for your business are made from/to different locations.
If you need to edit an existing location, just click on the blue button "Edit".