...
This section is provided for merchants that use the Catalog feature. Here, you can enter attribute for each of your items that will appear on your Catalog page. Until you have created attributes, you'll see the familiar "no attributes have been defined...defined…" notice.
Click the "New Attribute" button to create an attribute. The following screen will appear. 
In the new attribute screen, enter the Name, Value(s) and Type (20 character max). Then click the Save button.
...