Standard Online Sales Sequence

The sequence in brief

1. 客户查看您的在线 目录
2. 顾客将商品添加到 购物车
3. 客户继续 查看
4. 系统计算 货运 和 销售税, if any.
5. Customer pays through a 支付网关 (or one of other payment methods)
6. 商家收到 订单通知 和 payment reciept 通过电子邮件
7. Merchant ships the goods.

From your customers perspective

It is helpful to view things from your customers perspective, this is how it might proceed from their point of view 

1. The customer may click a product classification link first
2. 顾客可以搜索或浏览您的产品
3. Then click on a product title for more information
4. Click on the "buy" button to add this product to their shopping cart
5. Change the quantity and press "click update"
6. Continue shopping perhaps adding additional items to their cart, or...
7. Enter a delivery address
8. Tax and shipping charges are automatically calculated, if any
9. Enter remaining order details (you may collect information about the order such as size or colour) 
10. They the choose their payment method (an order will then be emailed to you the merchant)
11. The customer then completes the payment by their chosen method (If the customer choses "credit card", then a secure form will appear to collect credit card details)

After you have received confirmation of payment you can then ship the goods

Once you have set up your shopping cart system it is a great idea to navigate through the above processes. 
Is it smooth and enjoyable?  Are their any changes you think could improve it? 
Testing and becoming familiar with your own system will enable you to understand and thus effectively communicate with your customers