Securing and unsecured network

I have a Netgear 834GT router operating on Windows XP Pro op system.
I had occasion to reset the Netgear router (small hole & paperclip)
When I look at the available networks, I see 3 or 4 neighbours all secured.
I also see my Netgear network but it is unsecured.
Q. How do I secure my netork so that only I can logon?
Thanks for any help

all sorted now.

The easiest way to secure your router is to follow the steps in the setup....connect to the builtin www admin page of the device. Then enter a key for WEP or WPA2. Use that same key in your laptop.