Just bought a new iMac (10.5) and would like to setup a network Printer. Help?

I finally bought the new iMac running Leopard 10.5 and I would like to setup a printer to act as the network printer so my wife can print to it from her 1mac which runs an earlier version (10.3 I believe). I run the computers over my wireless home network using Linksys and coverage seems to be fine. My question is.... do I need to buy a printer with network card so she can print to it, or can I connect a non-network printer via USB from my new iMac and share it so she can print to it? I bought the new Lexmark X4550 network printer but it does not support Leopard and it chugs ink, so I would like to set this new environment up with a laser printer. Any istance is appreciated!