You'll need a wireless Cable Router to go with the modem NTL supply. You can't use an ADSL modem with NTL nor one they don't supply.
Then you just plug your router into the NTL modem, once the NTL connection is running, set the router up and then you'll effectively have wireless internet.
That LT has integrated wifi (g) but make sure it's turned on by pressing Fn+F8 before trying to find networks!
HTH