Hello geocan,
We have a knowledge base article on setting up import duty to calculate and track automatically. Review these steps for your setup.
For freight, you can track the Freight Expense and Freight Revenue automatically on any invoice. First make sure you link the freight accounts in your Payables and Receivables settings (Setup, Settings, Payables / Receivables, Linked Accounts.) Then enter the freight amount in the freight field toward the total of the Purchase or Sales invoice (if you are only paying or charging freight the invoice body would be blank except for the freight charge which is fine also.)
This is one method. The duty import article briefly touches on adding duty directly to the purchase price. You may wish to try both methods in a test company before proceeding in your actual data file.
