This is a short step by step tutorial to setup a Windows XP computer to print to a shared printer connected to a Mac.

1) In Mac OS X, set the printer to shared.
2) Enable Printer Sharing and Windows Sharing in the Services preference.
3) From Windows XP, first make sure Windows recognized the Mac as a Windows SMB share.
4) Then from inside Printers and Faxes, click Add New Printer and choose the printer from the workgroup.
5) If asked to install a driver, select any Postscript driver.