Pendulums consist of a weight, or bob, which hangs freely from a chain or string. Many people prefer to use a piece of jewlery, usually something they wear on a chain around their neck.Pendulums can be made out of mostly anything. (Mine is a necklace chain with a small fishing weight on the end) Some form of handle is may also be attached to the upper end of the chain to decrease the chance that the direction of movement would be caused by the person's subconcious.  However, the subconcious, as the person's intuitive self, may influence, and give correct answers, through the pendulum.  Spirits, your Higher Self, or even the pendulum itself may provide the answers you seek.  Like any divination tool, however, it may be influenced by lower spirits who may attempt to lie to you.  Just like asking a human, you should be careful who you choose to get answers from.  Blessing the pendulum should decrease the chances of a mal-intented spirit influencing the pendulum.

Before each session, the pendulum should be blessed in whatever way you feel comfortable with, from stating that only higher beings (or whatever being you wish to contact) may influence the pendulum, to smudging (burning incense) and other purification techniques.  The pendulum may also be purified after the session, to remove any residue the spirit may have left behind which may influence the next session.

The pendulum handle or chain should be held loosely between the thumb and first finger, and if the circle (see diagram below) is used, the bob should be held approximately 1 inch above the paper.  You can also use it without the circle, and just specify (or let the pendulum specify) which direction means what. Always program the pendulum at the beginning of the session before asking your questions.  "Show me yes" Should cause it to swing in one direction; "Show me No" should cause it to swing in a different direction.  It is also good to tell it to "Go to center" or "Stop" between questions, so that the swing of the pendulum won't be influenced by the last question's response.  Once programmed, ask the pendulum if it wishes to work with you. Ask a few trial questions to make sure its working properly. ("Is my name (your name)?" v.s. "Is my name Superman?")

It is important that questions be phrased clearly, so that no misinterpretation can be made.  This goes for all divination techniques.  "Is it going to rain?" is unclear.  "Is it going to rain in Los Angeles today?" is much more apt to get a correct response.  If, after several questions, the pendulum starts swinging in random directions, ask it if it wishes to continue the session.  If not, put the pendulum away and try again another time.

Here is an example of a pendulum circle, which may be printed out or copied for personal use.

 
For these, the Pendulum will swing back and forth in the direction of the arrow:
Yes: Indicates a Yes response to a Yes/No Question.
No: Indicates a No response to a Yes/No Question.
Maybe: Indicates a Maybe response to a Yes/No Question.
Another question may be asked if further clarification is necessary.
DWA: Don't Wish to Answer.

For these, the Pendulum will swing in a circular motion in the direction of the arrow:

NA: Not Applicable - You don't need to know.
RQ: Rephrase Question
There is also a Ouji like verison of the pendulum. Write on a piece of paper with the letters and numbers on it and hang the pendulum over the paper. It is known, though, this is more dangerous than just using the Ouji board.