In the "settings" menu, the first tab is WIFI. From that tab you'll see a toggle switch in the upper right hand corner. Press the right dirctional key on the remote to highlight that switch. Switch it ON.
Now select your wireless network. Use the on-screen keyboard to enter the password.
If you are having issues typing in the password, it is possible that the input method isn't correctly set. To do so, do this first:
After you have set up your input method, you should be able to input your password now.
Tip: Use the back button after inputting the password to exit the on-screen keyboard mode and back on to the "connect" prompt.