[plug] What is most important?

[Timothy White]

IMHO the best way to learn is to do. For me that meant building a
server, that did everything I wanted it to. By doing it on a dummy box
you have room for mistakes and you get the hands on.
I set up a box running a Domain (samba) acting as the PDC, with DNS
(bind9), mail servers....
I initially built my server with Debian then later with Ubuntu and
slowly learnt new things, LDAP Authentication and how to do some
things with different applications (Exim .vs. Postfix, Different
Webmail...)

One last point. After testing your server, test it with a number of
clients and try and make it die by doing stuff that users shouldn't.
I've had problems before with moving applications as well, a service I
was providing valid to work on the new server, it would seg fault even
though it was the same version, same architecture, same config files,
just different hardware, but it should have worked. It was enough
incentive to finally remove that service and start building a custom
one that was better suited.

Tim