This fantastic little device has so many uses and is so easy to setup that I'm sure a trained monkey could do it.
First off you've got repeater mode - simply scan for wireless networks, connect to your existing one and let the gizmo reboot and you've got a range extender that's super fast.
Then you've got access point mode - connect with a cable to your network and follow the wizard and you've created a wireless network.
Finally you've got ethernet adapter mode - again, follow the wizard and connect to your existing wireless network. You can then connect a non-wifi enabled device with a network cable to the N66 and you've got access to the internet and your network.
There's a very cool blue light which can be dimmed or turned off altogether and wall mounting holes on the back.
I've had this for a couple of months now and have had occasion to use it in each mode on several occasions and each time it just works flawlessly.