My parents, after hemming and hawing whilst I was in high school about my choice of careers, have finally accepted that, yes, this is what I'm doing with my life. A dozen years later, they're showing their support in what ways they can; for Christmas this year, they got me
The Stage Management Handbook by Daniel A. Ionazzi. I'm just now reading it. There's some good examples of forms in there, though I'm finding the rest of it a little simplsitic for where I am in my career (I really don't need a reminder as to what goes in a prompt script, or what "plaster line" means). I just ran across the two most helpful sentences for the rehearsal part of the job.
You will perform your job better if you understand that you are managing change. You must learn to love chaos.
This is something that I know I have a problem with, and try to be conscious of it, and conquer it more, every show. I've just never seen it in such simple, eloquent terms, before.
So, regardless of what you thought of the rest of the book, what's the best, quick standalone advice you've gotten from a SM book, or any book, for that matter.