Check out the official Miva Merchant demo store:

Storefront:
http://www.miva.com/products/demo/Merchant/merchant.mvc

Administration area:
http://www.miva.com/products/demo/Merchant/admin.mvc

Basic directions:

1) When you go into the admin section click on the triangle next to "Stores" then click on the triangle next to the store name "Miva Fresh".

2) Click on the word "Products" to see and edit the products. Then click on the round "paper & arrow" icon to the left of each product name to edit an individual item.

3) Click on "Order Processing". then click on an individual invoice to see the customer info. You can actually place an order in the storefront and then go in and see your invoice info. It will also send you the confirmation email that the customer will get. **Do not put in your reall address and personal info! But DO use a real email address to see the confirmation email**