[exim] virtual users/domains with postgres

I have only ever setup a mail server once before, and I followed a very
specific document.  It was courier, which took care of everything.  I used
postgres for the virtual users/domains.  But that was 3 years ago, and I
forget everything.

I want to setup exim to be my smtp server for machines on my subnet, and  a
pop server.  I want postgres to handle the virtual users and domains.  At
somepoint I would like to add virscanning and spam checking.

I am a little overwhelmed by what to do next.  I have exim installed, and
postgres installed.

exim documentation is a little lite and very general (or I am looking  in the
wrong spot).  Does anyone know of a good document for setting up exim with
virtual users?  This link
(http://www.xmn-berlin.de/~marte/exim/exim4_mysql_amavis_spamassasin.html)
has me somewhat pointed in the right direction, but I could use  a little
more help.

Any help would be great, thanks,

~S