Site Settings
How do I enable 'Free Shipping' for products?
To do this click 'Order Total Modules' under 'Site Settings'. Then press 'Shipping' and install the module if not already installed. Press the 'edit' button on the right and set the 'Allow Free Shipping' field to 'true'.
Then set the dollar amount for orders to receive free shipping. Press 'update' and free shipping will be a selection for customers at time of checkout.