One might ask how many devices does he want to connect to the internet. All via ethernet cable might be easiest. If he has 4 high speed switch ports and a single uplink port on the comcast and if he has 4 or fewer devices to connect then just use the comcast router.
If he has more devices than high speed switch ports then add the netgear router.
heres the pics i tried to drop frm gmail unsuccessfully earlier... maybe thatll help you gentlemen out....
http://postimg.org/image/4ss9hvja5/6e93b713/http://postimg.org/image/4rm34ogq5/fa5f5c12/http://postimg.org/image/5kyoxamr1/f996df4f/now of course ive obviously changed up that one ethernet connection in between the comcast and netgear to the regular lan from that designated internet port....
wait, hold on, the comcast and netgear are side by side?
i figured they was across the room..
doesnt the comcast router have 4 ports?
lets just hit the basics.. lets try to get the s3s working individually.
unplug everything..
plug one s3 into the COMCAST router..
set it to IP 192.168.1.200 < this makes it easy.
set the DNS to 192.168.1.1
set the gateway to 192.168.1.1
and see what happens.