You could go to
www.download.com and find a free or cheap proxy program. A proxy will help distribute the Internet connection to all the machines.
I think the following would be a complete list of what you need:
The Internet connection itself. Dial-up, DSL, cable-modem, etc.
The computers, each with a network card.
Network cables (the standard cable is called UTP category 5 (or 5e), with RJ-45 connectors on each end).
A hub or switch to plug the cables into.
The proxy program.
A "server" computer, the one that has the proxy program, needs to be on. If it is connected to the DSL via a network card, you may need a second network card for the internal network.
You can assign the computers in your network private IP addresses, for example, 10.0.0.1, 10.0.0.2, etc.
Another option, which a colleague at Cisco Networking Academy brought to my attention, would be a cheap router. This may be more convenient than keeping a computer on all the time. However, I am not yet sure about all the configuration details.
HTH,
Hilmar.
Difference in opinions hath cost many millions of lives: for instance, whether flesh be bread, or bread be flesh; whether whistling be a vice or a virtue; whether it be better to kiss a post, or throw it into the fire... (from Gulliver's Travels)