First, I integrate paypal and add Products Catalog Management.
Main role of shopping site is to classify according to kinds, price and quality, and checkout process with payment gateway integration.
So I make catalog about products and to manage catalog.
Also integrated paypal.
Second, User Accounts and Management, Product Reviews and Ratings.
Register and login by gmail and classify by role(admin and user).
also remember cart, favourate and user history to use localStorage of google property.
Third, Analytics and Reporting.
In Management page, add analytics and reporting about sales.
CHECK!