This is a (quite long, LOL :D) tutorial I wrote on the subject and I believe it covers most user scenarios, so it uses safe methods (known to work in generic scenarios, when the printer's manufacturer and model are unknown). I also tried to write it as plain (simple) as I possibly could, so that even regular users (users that are not tech wizards, but can find their way around a computer and can probably install a distro like Ubuntu on a PC) can configure the Linux print server and add the shared printer on a Windows install.
You can download the tutorial in PDF and DOC from here or here. Also, here are the plain (unarchived) PDF and DOC files.
I hope this tutorial helps users that have given up using their old (but working) printers, just because they don't have x64 (64-bit) Windows drivers :).