You need tclick on security under the wireless setting you need to select the type of security. You mentioned WEp or WPA. Select WPA. If it has it select WPA2. It will ask for a password or key. Enter a password in here. Make it hard to guess with numbers and letters about 10 or more long. When you do a save the router might restart. You should then loose your wireless connection to it. You will need to go into the wireless settings on your laptop, find your network again and then enter the password when prompted. Just like you did when you first connected the laptop to the wireless except this time it will ask for the password.
That pdf manual is very basic and does nothing to help make everyone's wireless networks secure.
I just found this for you
http://www.peakhardware.com/DB/FAQ/F...g-reviewed.htm
If you go to this page you can see all the guides at the bottom of the page
http://www.peakhardware.com/products...il.asp?PAID=48
This looks like the full manual for your router
http://www.peakhardware.com.tw/DB/Do...uterManual.pdf