"Cable Modem connected via USB"
I didn't believe that to be possible; cable modems use an Ethernet interface because cable services use the PPPoE protocol.
Let's assume for a minute that you actually have an Ethernet modem:
1) Run an RJ45 (Ethernet cable) from the modem to router.
2) Run another RJ45 from the router to a client (PC).
3) Open a browser and enter the router's IP (I think Netgears use 192.168.1.1, though it might be 0.1; it's ages since I last used one)
4) Configure the router as per the manual.
5) If you intend to set up a wireless link on the SAME client that you used to configure the router, remove the RJ45 now.
6) Install the wireless adapter on the chosen client PC, following these instructions: click here