[Fyron]

Yes, you will need cat 5 cables. The cable modem will need to be hooked into the uplink port on the d-link router. Is it a wireless router? If not, each computer will need to be connected to the router via cat 5 cables. If so, all computers lacking wireless network cards will need to be hooked in via cat 5 cable.

You will need to configure the wireless router to accept the notebook computer over the wireless network. It is quite possible that the router has MAC address filtering enabled, which prevents any wireless network device from connecting to it unless it has been explicitly authorized. I don't know about d-link routers, but with netgear, you can go to a web browser on a PC connected to the network and type in the address 192.168.0.1 to interface with the router configuration. You will need to know the login id and password. Did you get a manual with the router? If not, you might want to search Online on the D-Like web site for one.