Please find below steps to forwarding…

1. Login into godaddy.
2. Go to “My account” select “Mange domain”.
3. In domain settings see “Forwarding” section click on “Manage” under Domain.
4. In Forwarding and Masking page “Add Forwarding”.
5. Within “Add Forwarding” add domain name with http://www.my-domain.com with 301(Permanent).
6. Please check the “Name servers” checkbox weather you need to update “Name servers” or not.
7. It will take around 48 hours to propagate.