If you want more than one computer to have broadband access, without a "host" PC having to be running, then you need a "Router".
The type of router depends on:
a) the type of broadband - Cable (NTL / Telewest) or ADSL via the phone line.
b) whether you want one or both computers to connect "wirelessly". If not, a "wired" router will suffice.
For a wired connection, a PC requires a network adapter (an RJ45 ethernet port). For wireless, it needs a "Wireless Network Adapter". The laptop you get may well be equiped already with both types of adapter.
<<< the ether card would connect to a hub? and the pc then could also connect? >>>
No, both computers connect to the router. The router connects directly to the ISP (not one of the computers) and each computer gets its internet access over the LAN (Local Area Network) from the router.