As the thread name suggests i want to connect 2 pc's and my xbox 360 to my cable modem. Currently i have my modem linked to my main pc via a usb cable, then from my main pc to the one in my bedroom via an Ethernet cable. I would like to know how i can link my xbox 360 into this network so that all three devices can be online at the same time (at the moment i have to swap the Ethernet cable between my secondary pc and 360, so one or the other is online) or have any of them online independently without the need for my main pc to be switched on. I realise i need some extra equipment but am a bit confused on what to buy...Router?...Hub?...Cables?..etc.
I would prefer a wired connection as the wireless adapters would cost too much.
Sorry if this is a stupid question, but i would like some advice before i part with my hard earned cash.

.
Thanks in advance!