Some people call it dowsing, others call it divining, but when you use the movement of a pendulum in response to a question, you are balancing the intuitive with the rational part of you. When I was a child living in the country, dowsing was done with a stick or tree branch held in front of the dowser who would walk a patch of ground looking for a likely place to dig a well. Today, pendulums are created by hanging from a thread or thin chain, an evenly balanced weight that ideally tapers toward a point.
The dowser calibrates a pendulum by asking the direction it moves for “yes” and “no” responses to a question. After the movements show consistency, the dowser can ask questions and wait for the pendulum to answer.
There are a number of books available that describe the technique of dowsing. Many also have charts that can be used to calibrate responses. For more information, The Pendulum Kit by Sig Lonegren has a pendulum and book with exercises designed to increase your dowsing skills.
Pendulum Power Magic by Roberto Gadini has nice large color charts and some fun exercises.
The Practical Pendulum Book by D. Jurriaanse also has many charts that make learning to use your pendulum an enjoyable process.