Update: for anyone who is considering a print server for a Mac, read on.
I've taken the plunge and bought a D-Link DP-301U print server. There are issues affecting some printers when connected via a print server so it may be wise to check with the manufacturer first before going down this route.
I have a Lexmark E120 laser printer - not the network version hence the need for a print server! The Lexmark supplied CD is for both printers, E120 and E120n, and contains the E120n driver. When using this driver, the E120 will not work as a USB device under Mac OS, so beware! However, my solution (below) will also work with a stand-alone printer.
I've now got everything working after several frustrating hours. The problem turned out to be with Lexmark's own printer driver - it may work with the E120n (network) version of this machine but I can't get a stand-alone printer connected via a print server to work, so Gutenprint v5.1.3 eventually came to the rescue. Tucked away in there happens to be a generic PCL driver and, as the E120 is a PCL printer, this works.
If you are unaware of Gutenprint drivers, check out this site. See here for a list of supported printers.
Fred