You would set up your first router and make sure you can connect to it. Be sure to set an SSID you can differentiate from others nearby, and an encryption key.
Set your Netgear to repeater mode with the same SSID and Encryption key (and type). DHCP should be disabled when you do this, if not disable it. You will supply the IP address of the first router as the DHCP server. Reboot the router and log back into it. Do a Site survey to connect to the first router. Don't forget to apply changes on each page before you navigate away from it!!!
All routers are slightly different as to how you log in to them. Feel free to start the process. If you get stuck, do your best to describe what you are seeing. It would help to have model numbers so I can look up the manuals.
I'll be here,
Good Luck