The WordPress e-Commerce Plugin is an industrial strength elegant easy to use fully-featured shopping cart application perfect for selling your products and services, or collecting payments and fees online.

We are pleased to offer expanded documentation, including quick start tips, highlighted in yellow. You can also find many answers on the WP e-Commerce Support Forum, which is quite active.

External Resources:

Plugin Documentation

For the most recent WP e-Commerce Plugin documentation head over to the docs.getshopped.org website.

The Book. 

Follow a practical, step-by-step guide packed with screenshots to ensure your store is created and deployed successfully

https://www.packtpub.com/wordpress-2-9-e-commerce/book

WP e-Commerce SEO Manual

Dave from Dew Point Productions has written an SEO manual for WP e-Commerce. You can download the SEO Manual from his website.