Networking two computers?

Hello Everyone,

I want to connect two home office machines running WinXP Pro. They sit next
to each other and are used by one person. I want to use the second computer
as a backup and move data from my new computer to my old computer.

I use a cable modem and want the benefit of a hardware firewall for the
machines. My new computer has a Network card but my old machine does not
have one yet.

My guess is Ethernet and an a router. Can someone suggest some good hardware
to do this job?

Thanks,

Bob