freePBX on Asterisk virtual machine


I am not sure where to start with this install, I have the webUI up and running - so its more the config that needs to be organised. I am using Asterisk to be a intermediate between a Lync 2010 box, and a Samsung 7200.

The FreePBX box needs to be able to transfer calls to and from the Samsung system to the Lync box. If I assume all the settings are correct on the Lync and Samsung, what to I need to create on the FreePBX box? Is it just a Trunk? or do I manually have to add each phone number?