Shipping and Payment methods in Magento
You can configure the shipping and the payment methods for your script through the admin area -> System -> Configuration -> Sales:
In this tutorial we will illustrate how to enable the USPS shipping method and the credit card payment method. Before enabling the shipping method you should configure the shipping settings:
The fields there are self-explanatory.Once you are ready, click on the Shipping Methods -> USPS link:
Enable the shipping method, enter the Gateway URL and the UserID. The next options allow you to describe the packages which you need to be delivered.
Then you can define the handling fee. It can be fixed or calculated on the percent basis. After this you can pick the allowed delivery methods. You can configure a free shipping method and define whether there is a minimum purchase sum for it.
At the end you can define the countries for which the shipping is supported and the default error message in case the service is refused.The credit card payment method can be configured through the Payment Methods -> Saved CC section:
Enable the method, enter its name, set the new order status, pick the supported credit cards, decide whether the credit card verification is required, define from which countries to accept payments and the range of the accepted payments.