The catalog look up is the heart of PSS in regards to data management. This is where you will be spending most of your time manipulating products and creating listings. You will want to get familiar with the different filters available on the left hand side to help search for the appropriate products list in an efficient manner. The "Status" filters are good for reducing the results depending on what module you are working on. For instance "eBay Status" > "Not Listed", will only show you results for products that are not currently listed.