In answer to your questions …
- The user documentation is very detailed at Get Shopped
- There are a number of articles for theme designers and developers to work their way through and here too
- You probably really want to read the conditional tag articles to include in your custom theme
- Had you found the the WP-ecommerce templates located at `/wp-content/plugins/wp-e-commerce/wpsc-theme’ you’ll find these easiest for integrating
If you’ve got this far in the design process, I sympathise with you … but really … Why design first and build last when it seems you’ve not used the product before?