This router is one of the easiest to use ;)
First you need to know the routers SSID and WPA/WPA2 password: do do this login to the router by typing 192.168.0.1 into the web browser and use the username "admin" and password "admin" or "password" - without the quotes ;).
Once logged into router she needs to find the wireless settings. Usualy by clicking setup.
Change the SSID to a name of your choice and then select WPA or WPA2 (the later is better). Type in a long password, taking note of it. Then click apply and log out of router.
On the laptop right click on the little TVs next to the clock (bottom right of screen.) Then select connect to a network. Windows will search for wireless networks in the area. Select the one which is the same as the SSID as you typed in on the router. Then type in the long password from before , then click connect.
You should now be connected wirelessly.