splitting external dsl

I have my external dsl modem connected to a hub, from which, I have three pcs connected to the hub, which share the dsl line. If your ISP gives you a dynamic ip (DHCP), you could easily just get a hub to share the DSL line, that way you could add another computer if you ever want to.

Depends on the network cards in your systems. If you want to share files between them at the fastest speeds, a 10/100 Mbit hub will work quite well. The cable modem's ethernet port is only 10Mbps so a 10Mbps hub will do the trick as well (but the computers will only talk to each other at 10Mbps). For the price difference, a 10/100 hub will work well in your situation and it shouldn't cost more than $50-$60 for a 5 port 10/100 hub. A 3 port hub would also work, but you won't find one with that few ports... Each port will correspond to a device on the network, so make sure you get one that will allow for expansion (network printer, another networked PC, etc...).