don't know of any books, but i do use one i made (amethyst point), frequently, to find lost objects. first i connect with my spirit guides, and let the pendulum point the way. as far as which of the two directions to look in, i feel a subtle tug in the correct one. funny thing is, if i don't properly connect, it doesn't work until i do.
i also sometimes use it for simple "yes or no questions".
Most of the books I've gotten on pendulums are more charts to use then telling about the pendulum. I will list a some of them and you can check them out. A little book of Pendulum Magic by D. J. Conway, Pendulum Workbook by Markus Schirner, The Practical Pendulum Book by Jurriaanse. I like the Pendulum Workbook just for the wide range of charts, but I think your looking for some more a long the line of the Pendulum Magic. Hope it helps.
I need to pratices more with my pendulum cause I find somedays I'm very actuate then others I'm so far off in left field its not funny. The strange part with my pendulum is I have a friend who is pregnate. Before the ultrasound she asked me if it was a boy or girl. It swung boy. Well, the ultrasound showed a girl, but I've asked my pendulum several time after this and it still says boy. Not sure if it's cause of me or if it's cause they want a boy?!? Let me know if you can shed some light on this. Thanks