In the documentation:
1.x Tutorials.
http://www.ubercart.org/docs/user/561/tutorials
2.x Screen shots and video on selling digital files.
http://www.ubercart.org/docs/user/10966/selling_files
2.x Video guide to creating a product.
http://www.ubercart.org/docs/user/10960/basic_product_creation
2.x Video guides to attributes and options.
http://www.ubercart.org/docs/user/10961/product_attributes_and_options
2.x Video guide to building a catalog.
http://www.ubercart.org/docs/user/10964/building_product_catalog
In the contributions section, scattered around, some under 'other'.
http://www.ubercart.org/contrib?filter0=Other&filter1=**ALL**&filter2=**...