I have a similar setup. Connect your mac to your printer. On each pc, download Bonjour for windows (its free on apple's website - just google bonjour for windows), and it's very self explanatory from there. It works perfectly. Leave it to apple to straighten out windows networking mess. The only downside is that the mac has to be awake in order to print from any of the computers.
I have cable modem service going into a Netgear WPN824 Router. With this router I've been trying to home network a Dell Dimension PC (running XP Pro), an IBM Thinkpad notebook (running XP Pro), an iMac (recent purchase), and an HP PSC2510 all-in-one printer. I'd like all three computers to be able to print to the HP printer; if necessary I can connect the iMac directly to the printer via USB cable (then use the computer to share the printer), but ideally would like everything to run through the router. I have had no problem getting internet access to all computers through this router, but the printer (and file sharing)? Yecch.
This doesn't sound impossible, and yet I've seemingly tried everything for many, many hours to no avail. Can anyone much smarter than I am give me a step-by-step on how to get this accomplished? Even if I can get this network setup like this, due to the Mac/PC thing can I have any hope that it will be stable for more than a day?