How do I add a thumbnail image to a category page?
To assign a thumbnail image to category or sub-category, visit
Admin > Catalog > Categories > List and select the category or subcategory you would like to edit
Select an existing category or sub-category that you wish to edit, or click Add Category
On the Category page, click on the tab Category Link / Image:
Click Choose File for the Thumbnail View Image. Select the image from your computer.
Once you are finished, click Add Category or Update