There should be directions in your routers manual, if you dont have one, search the companys website. Usually what you do is type in the IP of your router, usually 188.8.131.52 or
Then you type in admin (user) and "usually" admin or you dont even type in a pass. Go to Encryption/Security, WAP, and a 64bit should be fine.
You can have it generate one for you, then copy that code somewhere, and save your settings. Now, only for the first time, when you...