Have a look at the next tutorial below, to learn how to set up your POS items links, and create recipes. This will enable you to see the cost of all your POS items (updated from latest stock costing automatically if you are using the ordering feature) and the resulting cost of goods (COGS).

After you have completed the set up your stock items will start decrementing from inventory in your stock takes (which will be the next video).
(Remember to change the quality of the video on Youtube to 720p to view in HD, and then watch in full screen mode so you don't miss anything!)