Hi @blaise, that is great to hear, we've always believed schools are a great place for Air Quality Eggs to live for a lot of reasons!
The power interface to the Air Quality Egg is a male Type A USB cable about 3 feet long. It ships with a wall adapter power supply that has a Type A USB receptacle, similar to a lot of phone chargers these days.
There are a couple of ways to extend the power cable if you need more length. The first would be to use a conventional extension chord and plug the wall adapter into it. However, if you expect low temperatures (i.e. below 0C) , a better approach would be to use a USB extension cable to lengthen the USB cable and plug in your wall adapter indoors. If you search on the internet for USB extension you'll find a variety of pretty inexpensive options at various lengths, like this one for example.
As far as ways to secure / mount the Egg, there are two small "tunnels" at the top of the enclosure that were meant so you can thread something durable through to make a loop and hang on a hook (e.g. using parachute cord). Another possibility is to use some heavy duty outdoor double-stick mounting tape to stick the enclosure to an exterior wall (e.g. 3M 4011). There are other creative possibilities, I'm sure.