As recap said you need RJ45 Cables Preferably CAT 5e. If you are only going to connect one or two computers and they are fairly close you can buy these made up in various lengths at your local computer shop. However if they are any distance apart Ie different floors or you have a lot of computers , say over five or so , then you might be better buyiig the cable and the connectors and a RJ54 Crimping tool and making your own.
Its a bit tricky but a couple of attempts and youll get the hang of it. There are 8 wires in the cable, the important thing is that they are in the same sequence on each end in the plug. They do not have to be in any particular sequence, just so long as they are the same. Any half decent shop where you can get this stuff will show yo how to do it. Its worth doing your own as its is much cheaper in the long run. And you can call yourself a network engineer!!!! Hope this helps Your Kitz E Kat