To define free shipping:
- Select System > Configuration > Shipping Methods.
- Expand the Free Shipping section to enable free shipping with optional minimum order amount.
- In the Enabled field select Yes to enable the method.
- In the Minimum order amount field specify the amount for an order over which shipping is provided free of charge.
- In the Ship to applicable countries field, you can select the Specific Countries option to enable access to the field under it in which you can select specific countries, so that free shipping is only applied to the relevant countries or you can select the All Allowed Countries to specify that free shipping is available for users from all countries.
For futher details and close up help, go to www.magentocommerce.com, or check out the downloadable Magento Community 1.7 User Guide.