It works like this:
Virgin Broadband modem ---> Wired or wireless router----> All computers hook up to router.
Your computers connect to the router either by ethernet or if you have purchased a wireless router wirelessly.
If the laptop has wirless you can connect it anywhere round your house. Your PC might not have a wireless card so in that case you can hook that at the back of the router using ethernet cable. You can have both wired and wireless.
As others have mentioed, when buying make sure you go for a router that is not ADSL.
Some good recomendations here:
http://www.cableforum.co.uk/board/87...info-here.html