LAN Networking?

There is lots of info you need to provide, do you need internet access? File and/or printer sharing? Wireless?

If none of those, just get a switch, run ethernet cables to the computers using jacks, hook up the jacks to a central point, connect them to the switch, assign them all IPs manually starting with 192.168.1.2 (to save .1 if you ever get a Router).