Ok, here's an easy setup that I've used over and over and it's never failed me yet. Go here: http://windowsxp.mvps.org/netbeui.htm
Download netbeui, it's NOT NETBIOS, it's netbeui. It's an old network protocol that works automagically. Install it on all three machines, then reboot them all. They will automagically see each other and share anything you have marked to be shared from each computer.
As for printers and scanners, you have to "share" them from the computer they are hooked up to, then install them or add them to your wireless ones via the printer (for example) control. Just go to start/settings/printers and "add a new printer", but when given the choice, tell it it's a network printer. It should go ahead and add the drivers.
In zonealarm, be sure, under the firewall tab, to add an ip range of whatever your network is on all computers that have that firewall, and run the network setup wizard for zonealarm as well.
That's all I do and I have five so far and add more as I get them in for repair. I've also used it comercially to set up small office networks, up to 12 computer so far.
One last thought, be sure you've antivirused them all as well, before you connect them because if one gets infected you're opening them all up to potential infection if they're on the network.
Best of luck!
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