Shopper want to make sure all the details of their orders are correct. An 'Order Summary' lets them review the products that have been selected, the total cost, and the shipping information. If any information is incorrect, customers should be able to edit the order summary by changing their orders or any of the delivery or billing information. Customers want to see that the information they entered will be used correctly so that they don't find out later, for exam, that the shipping and billing addresses were reversed. Give them an Order Confirmation and Thank-you that confirms their order, gives the order number, and says how to contact the company, all on one page so that they can print it out for their records.
The Design of sites: Patterns, principles, and processes for crafting a customer-centered Web experience. Douglas K. Van Duyne, James A. Landay, Jason I. Hong