Bruce,
NT PDCs support a feature where the windows printer drivers can be stored on the server, so you don't have to install them on each workstation. Samba 2.2.x also supports this feature, but I don't know if it's implemented in SME 5.1.2. I got it mostly working using the HOWTO referenced above (I wrote it), but even then it wasn't 100%, and I don't know much more than is in that document.