I have 3 PCs

http://www.geekgirls.com/windowsxp_home_network.htm

or

http://windowshelp.microsoft.com/Windows/en-US/help/76174f4a-7522-425a-9424-324dd299265e1033.mspx

or

http://video.google.com/videoplay?docid=-4885804885278005452#

You need to get a DSL or cable modem router or it maybe a separate router and a cable or DSL modem. Get an Intermet Service Provider and their recommended modem router combination also select a plan that suits your requirements (ie costs, broadband speed, and download limit). This modem router needs to be configured in accordance with the IPS settings.
If the modem router does not have at least 3 network RJ45 Ethernet ports then you will need a hub that has 6 or more ports.
The computers are then connected to the modem router with LAN cables. If there is not enough ports on the modem router then connect the computers to the hub and then connect a LAN cable from the hub to the Ethernet port on the modem router.
All the computers need to be in the same Workgroup, and the IP address have to be configured to obtain an IP address automatically and Obtain DNS server address automatically.
If you need to print from any computer, the printers need to be shared.
If you need to copy or move files between computers then the hard disks and or folders need to be configured for sharing.
If you need further information, please contact me.