If you have multiple locations, there are two key reports to help you manage inventory and sales across all of your shops.
This tool provides an easy way to see which titles are stocked at one store but not another - as well as how they are performing. This can help balance inventory across locations when needed while also maintaining the individual "personality" of each store. More here.
Location Performance Comparison
This tool allows you to compare your shops' performance relative to one another. The basic concept is similar to the Location Comparison above but at a higher level. For example, you can use Saved Filters and refinements to see which shop has the best turns for juvenile books. More here.