AmeriCommerce offers you two different ways of associating and uploading product pictures/images:

1. Provide the image path/location: using the product editor or import tool to associate the image with a product
2. Auto association - through which images are named in a particular format (using the product item number) and uploaded to a specific directory and they are automatically associated with the products.

To review both of these in detail please see the following knowledgbase articles:

How to upload a product picture using the product editor

How to setup auto association of product images