When I setup information for the contracts in "Agreements, Tax, and Banking" of iTunesConnect, I can not setup the "Contact info". This is because there is no contact showing when selecting the drop-down list as image blow shows. I have even created some users in "Users and Roles".
This should be a fairly easy fix. You don't see any contacts in the dropdown, because you haven't created any. To create contracts in iTunes connect, simply press the Add New Contact button, fill in the information and press save. This will then allow you to select the created contact in the dropdown.
Hope that helps, Julian