As your laptop has a wireless card you do not need a USB adapter as well.
As an NTL 'cable' customer you will have a modem already so you need a router as opposed to a combined modem router i.e. one with a modem built into it.
When I was with NTL I had one like this click here
which is wireless as well as wired.
Very easy to set up and great phone support if required.