First, your netgear router must be a cable router and not an adsl router. If you're not sure then just Google the make and model number then check some of the links you get. Otherwise post back here with the model number and someone will be able to advise you.
If it is a cable router then turn off the modem, router and computer (remove the power leads if necessary). The modem needs to be connected to your cable as it is now. Connect the modem to the uplink socket on the router by ethernet cable. Connect the computer to one of the other ethernet sockets on the router. Do the following in the stated order.
1. Switch on the modem and wait for the lights to settle. (this may take up to minute)
2. Next switch on the router and wait for its lights to become steady.
3. Finally boot up the computer.
That should be all there is to it. Once this is working you can log on to the router to set up the wireless side of things.