Addind Exchange to SBS2003

Hello all,

We currently have two servers, one sbs 2003 as the DC with the built in Exchange running on it and another server 2003 as a Member Server as a terminal server. I want to add a new Server 2003 with Exchange 2003 Standard to the domain. Will this conflict with the original Exchange on SBS? Do I add the new server to the domain then install Exchange on and configure it? Then do I migrate the users mailboxes across? I am new to exchange and am having trouble getting my head around it all so any help is appreciated.