The Catalog section of the administration tool is a pretty nifty piece of content management software. You can control your stock with a fine tooth comb from here, and although it is not complete on its own, using some of the community contributions to extend the default functionality provided should give you all the help you need to run and maintain the stock on your site; as mentioned, you may wish to look at EasyPopulate in order to upload a number of products at once.
Before we begin by looking at the subsections of the Catalog administration tool, there are a few things that you should know beforehand. Above and beyond the standard functionality provided, osCommerce also gives you a drop-down navigation list to help find your way around your data directory structure, as well as a search tool. If you open up the Catalog page, you will be presented with something like this:
Use the Search textbox (type in the name of the product or category and hit Enter) to find products or categories...