The structure of your webs-a-gogo online catalog is very similar to a "real world" store.  Your Catalog will have Departments (Sporting Goods, Housewares, Men's Clothing, etc) and within each Department will be Categories (Hunting, Fishing, Tableware, Appliances, Shirts, Pants, etc).  The Catalog Field Labels manager lets you add custom labels to your items depending on your product line or service type.  Your Catalog also has an Item Manager which is much like a "Stock Manager" that allows you to add and delete items from your Catalog.  The Icons below, found in your Control Center, link you to the different functions of your Catalog:

 

 

The basic concept is this.  You start by adding your Departments.  Then you add Categories to each Department.  Then you add field labels (if needed).  Then you add items to the Catalog within each Department and Category.