Did you mean Linux or LinkSys?
Seems like you might need a router like the
Linksys Wireless Access Point 4-Port Cable/DSL Router 802.11b ($70).
You plug it into your DSL modem then four computers can be plugged into it, through an old-fashioned 10/100 network cable. That's the "router" part. It routes traffic between each thing on a local network, to an outside larger network.
Then, you can also remove the cable and use a
wireless network card ($50) in any of the computers instead. As long as the DSL modem and the router are turned on, any computer can surf the web. Even your neighbors can access your network, if you don't turn on the router's security features!