I've also recently installed a NETGEAR DG834Gv2, and found another PPRuNe thread
here very helpful, as I cautiously try to increase the wireless security.
The text and screenshots on
THIS LINK provide some guidance on settings.
A note of caution that has been mentioned before; it's advisable to have at least one PC connected to the DG834 via a LAN cable, at least whilst you're setting up the security. If you only have a wireless connection during the procedure, and things go wrong, you could find yourself unable to communicate with your own router!