Wireless connection from a Belkin G wireless modem/router to laptops

Hi Everyone!

I'm not really knowledgable regarding computers but decided to take a
chance and change my ADSL modem to a wireless modem/router (Belkin G).
My broadband provider is Virgin.
The first stage went fine - I have one PC connected to the router via
cables and the inrenet connection works just fine. The problem started
when I tried to connect a laptop as a wireless connection. I'm not
really sure what I'm suppose to do to make it work...
I want to connect 2 laptops (both have windows xp, one have centrino
and one dual core). Do I need a networking card for them or they can
work without it (they are suppose to be wireless enable, aren't
they?!). One of the laptops (the centrino) is configurated to work with
NTL broadband. Can It work on both (not at the same time obviously
:-))?
I really don't know what to do and any help will be much appreciated!!!!