User account server how to?

[chombee]

Question about setting up an ubuntu server. We have four ubuntu machines
in our office/lab, and would like people to have user accounts which
they can access from any one of these machines, and would like the
accounts to be backed up. Obviously this requires an additional machine
to act as a server and to hold the user accounts. My university does
something like this 'network accounts' setup with fedora, so I know it's
possible, but have no idea how to do it. What are my options?

Thanks

P.S. In the meantime, everyone is just sharing one default account on
each machine. They keep complaining that the printer settings are
getting changed! Every time someone prints something with weird settings
those settings get remembered for that app and then the next person that
comes along has a problem printing until they realise they need to reset
the printing prefs of the app. Is there any way to prevent the printing
prefs from being remembered, have them stuck at some defaults?