[exim] Exim install on a replacement server...

Its time to upgrade the machine Exim lives on, and to be honest, it's a
slightly daunting task as apparently its been on the same machine for
nearly 7 years so there's loads of stuff on there that it does but
nobody really knows about etc... I've been doing a little admin on Exim
for a while now, but I've never had to install it all fresh
(SpamAssassin and Clam too), and I won't pretend to understand exactly
how it all works and fits together.

Has any one written or come across a reasonable 'getting an Exim mail
server working' guide? Any pointers and tips really appreciated. I've
installed the latest Centos, just because that was what I had to hand
but if anyone recommends something else I'm willing to give it a go.

Thanks, jc