Adding 2nd Exchange server

I have a W2K server with Exchange2K – I want to add a 2nd server to provide redundancy so if the existing server fails the users can still get to their email (and file shares). I’m looking for the simplest route as the onsite personel are not very computer literate!

What would be my best way of going about this?
Should I upgrade the existing server to the latest versions or is this unnecessary?

What is the simplest way to get Exchange to replicate between the 2 servers?