For those who have PLUS subscriptions or higher, the

Item Documents option found under Items gives you the ability to upload documents such as Catalog Books, Price Lists, and more.

You may begin by clicking the Upload  button.

Here, you'll choose the File Name, the Document Type, and you can add a Description if you'd like. 

When uploading a document, in addition to actually uploading your desired document (using the Select Document option), you can also choose a thumbnail to see when looking at your documents in Grid View (using the Thumbnail Image option).

Toggling between Grid and List view can be done using the buttons found to the left of the Upload button:

While in Grid View, you can save the document to your computer by clicking the Download  (1) icon when hovering over the document.

To copy a link to share with someone, click the Share (2) icon when hovering over the document.