Or, go to the the "Print and Fax" preference pane, select the "Sharing" tab at the top and check the box that says "Share these printers with other computers" on the mac that is connected to the printer. And make sure that the printer that you want to share has a checkbox next to it's name in that same window.
iBook G4 1 GHz, 768, Mac OS X (10.4.8), 20GB 4G iPod