Mac TCP/IP

I am putting together a small peer to peer network for a friends multimedia company. four Macs all running with DSL internet. Three parallel printers and a external cd writer which I am guessing will be a usb connection. My plan so far is to use a gateway for internet and a little device I found for the printer server. and this will all require tcp/ip.

I have tried to hook up the Mac TCP/IP network but it failed. I had the addressing all wrong. Can anyone give me some advice on IP addressing for this system?

Evan Short