Hi
the callsign Kestrel is used by an airline (off the top of my head can't remember which one).
As regards tips I would recommend buying the AIR BAND RADIO HANDBOOK published by Ian Allan. It will help make sense of what you hear. Although my copy is a few years old, I believe it is still published. Also has tips on how you can improve your reception, how to make home based aerials etc.
A good publication is also Radio User magazine which has loads of airband radio info - you should be ablew to get a copy from youtr local WH Smiths.
Enjoy the hobby and just remember to be sensible when you're out and about with your scanner.
Steve