Are you using CUPS? because if you are, and it's configured correctly, all you have to do is set up CUPS on the client computers (since you already did it once), and edit this section in /etc/cups/client.conf:
# ServerName: the hostname of your server. By default CUPS will use the
# hostname of the system or the value of the CUPS_SERVER environment
# variable. ONLY ONE SERVER NAME MAY BE SPECIFIED AT A TIME. To use
# more than one server you must use a local scheduler with browsing
# and possibly polling.
#
ServerName (Ip address of servercomputer)
if your not, and you want to, or need more information fast, take a look at this site:
http://www.cups.org/documentation.php