It's all in the second post of this thread, tosa, along with how to get there in the netgear router settings. Once in to the router setting on your computer click on Wireless Settings and from there go to LAN IP Setup. In here is a place called Address Reservation- this is where you would set up a specific IP address just for the PS3 using the MAC address of it as an Identifier for the router's benefit.
65% should normally be enough but the PS3's wifi card has proven to be a bit on the weak side- depending on how far away the router is from your system you may want to consider going wired or pick up a range extender to boost the signal.