When a user on our second Exchange server tries to log in to OWA using the first Exchange server address, they get kicked to our second server. Is there any way to have all of our users enter the same OWA address to login? Or have the first server pass the login to the second server so that the user doesn't have to log in again?

What you need is a Front-End server which accepts requests from clients and proxies them to the appropriate back-end server. Have a look through these docs: Front-End and Back-End Server Topology Guide for Exchange Server 2003 and Exchange 2000 Server http://technet.microsoft.com/en-us/library/aa996980(EXCHG.65).aspx