Advice on upgrading domain server and exchange server

[David M. Wolff]

I was just looking for some general advice and possible links to white papers
that might help me. My network (12 server and 300 workstations) is currently
running a windows 2000 domain controller and exchange 2000. I would like to
upgrade to a Windows 2003 (64 bit) domain controller and Exchange 2007. Would
it be better to upgrade my domain controller before my exchange server? Are
there any concerns about running adprep on my windows 2000 domain server so I
can add a windows 2003 backup domain controller? Once I have a windows 2003
backup domain controller can I just promote to be my primary domain
controller? Are their any problems I should anticipate?

Any help is greatly appreciated.

David Wolff