The pendulum is perhaps one of the simplest and most effective methods of divination existing today.
The basis of the pendulum is that you usually know the answer to the question you are asking. The only problem is that the answer is stored in your subconscious or psychic mind and your subconscious won't let your conscious mind have the information. The pendulum then, is a vehicle for moving information from your subconscious to your conscious.
They are extremely simple to use. To determine which way swings for yes and no, ask a question that has a definite 'yes' answer, Am I a female?' I find it is easiest to rest my elbow on the table with the pendulum hanging firmly between my fingers. This way the arm is stable and relaxed. Test you pendulum with 'no' questions also.
Once you have determined the directions for yes and no (this is usually the same with every pendulum you use) you can have an enormous amount of fun. Be mindful that your questions need to be very specific. 'Is it going to rain today?' is too ambiguous as it will certainly be raining somewhere. 'Is it going to rain today at my house?' is a better example.
Another way is to put several answers in separate envelopes and hold your pendulum over each one asking 'Is this the right answer?'
Once you become accustomed to the process it is quite an amazing thing to watch as they swing quite differently for everyone.