Creating shipping rates
Flat fee shipping rates can be set for different countries using the "Flat Fee Shipping" extension.
Choosing a shipping option
If multiple rates are set for a country they will appear as a dropdown field on the checkout form for the customer to choose.
Shipping rates are applied before the sub total, so modifiers that come after the sub total (like tax and coupon discounts) will be applied to shipping costs also.
Shipping relies on the "Addresses" extension because the customers shipping address country is used to select available shipping rates.