Meditation is a state of no-mind. It is your natural state, which you are aware of when your mind is totally silent. It is a state of total relaxation, the complete opposite of the 'inner stress', what is the cause of many diseases. Meditation can neither be done nor gained. In general, we often use the words meditate and meditation for practising meditation techniques, which prepare and help us to get in a meditation state. When you meditate, you bring your attention back to the presence, away from the mind, e.g. to the breath, body, sensory perception (listening, watching, ...).
Aside from the well-known silent meditations, there are numerous active meditations, in which body motion is an important factor. They contain an active phase and a subsequent rest period, in which you just relax and observe. In active meditations, you dance, sing, hop, breathe, shake your body, listen ... You have to find out, which meditation is most convenient for you. But one thing is clear: meditation should be fun!
Osho has introduced a lot of active meditations, which suit our modern, overstrained mind. These very strong meditations allow us, to get soon in a state of deep relaxation soon.
OSHO meditations: DYNAMIC MEDITATION™, KUNDALINI MEDITATION™, NATARAJ MEDITATION™, NADABRAHMA MEDITATION™, DEVAVANI MEDITATION™, GOURISHANKAR MEDITATION™, MANDALA MEDITATION™, NO DIMENSIONS MEDITATION™, CHAKRA SOUND MEDITATION™, GIBBERISH
-> Here you can find a description of these meditations: http://oshoworld.com/
Other meditations: buddhist meditations (Vipassana, Zen), christian meditations, Bodyscan, mandra chanting, contemplation, listening, dance and rhytm meditations, meditations of Eckhard Wunderle, own creation meditations, and i am working with the methods of Christian Meyer.
There is no preparatory knowledge needed to participate in any meditation, just come and find out :-)