Under the Catalog drop-down menu of your seller account, click the Add Products feature to create a new listing by matching to an existing product detail page in the Amazon catalog. You can also create a new detail page for a product that does not yet exist yet in the catalog and then create a listing for that product. For more information, go to Add one product at a time.
Amazon chooses what information to include on the product detail page based on manufacturer and seller contributions. For more information, go to Get to know the product detail page.
This is a very easy way to add a few listings or product pages; however, you cannot use this option to create multiple listings at a time or with some product categories. For information regarding bulk listing creation, go to Create listings in bulk.
After you create a listing, use Manage Inventory to make changes to listing or product data.