OK, as some of you may be aware, I'm trying to be a budding author. I'm working on something where characters (already known to be pilots) are in communication with ATC and other aircraft, and I want to get the lingo right. Is there a good translator/glossary/primer for ATC langauge, in particular the designation of callsings. I know the tail number is part of it, and calling the Concorde "speedbird" makes sense, but at what point does a plane become "heavy" and is that even a real term of just hollyweird sillies?

I've always treated the aircraft with a lot handwavium- it takes off, it flies, sometimes it bounces a little, every so often they even have to go around again. But I'd like to get some more detail.