You need to go to this page in the router interface click here
At the bottom where it says "Security option" choose WPA-PSK
Go to click here and formulate a password. Use the second one down for ultimate security Make sure you either print off the password or preferably put it on a memory stick or other removeable media as you will need it for the laptop.
Enter the password into the required field in the routers interface and click Apply.
Now go to the laptop and go Start > Control panel> Wireless Network Set up wizard and follow the wizard through entering the WPA passkey when requested.
That should be pretty much it.
Once you have the wireless network running OK you can make the connection more secure by changing the name of the wireless network from Netgear to something else and you can choose not to broadcast the name if you wish.
In addition if you wish you can restrict the machines permitted to connect, MAC adddress filtering.
I would also advise changing the routers password if not already done to make things a little more secure.
I hope this helps, can't be more specific as I no longer have the Netgear but it's pretty straightforward.