• Connect your PC to the router using an Ethernet cable.
• Open a web browser and enter the address
http://192.168.1.1
• The default username is ‘admin’. The default password is also ‘admin’.
^ from the manual
I don't know that router, that should get you into the admin pages, have a look round for wireless security settings and you will find the key
While you are there you can change the SSID to what ever you want and WPA is more secure than WEP but either will keep the chancers off