Windows 2003 Domain Redundancy

Hi
I have a Windows 2003 Domain with a single Domain Controller. It is the DNS & DHCP Server also.
I just recently added a 2nd Domain Controller just by running dcpromo.
I also made it the secondary DNS Server which seemed to work fine.
But if I disconnect the first DC then we cannot logon to the domain. There is no real redundancy in this case.
I have 2 questions here I hope someone can answer.

1. Is there an artical somewhere on how to setup another DC so that if the fist DC fails the second will continue as if nothing has happened?

2. What can be done regarding DHCP redundancy, as there can only be one active DHCP server on a network.

Thanks Glen