When you sit quietly with your eyes closed in darkness, your brain interprets this situation as a signal to start shutting itself down for sleep. Sleep inducing hormones such as melatonin are released at the same time your heart rate and circulation are reduced due to lack of movement. You feel swept away on a sea of quiet relaxation. This pleasant experience may be light sleep state hypnosis, not meditation at all, and thus does you little more good than taking a nap. Meditation means that you are relaxed as if sleeping, but your consciousness is fully and intensely awake. Therefore, if you meditate with your eyes closed, the room must remain brightly lit, so that a significant amount of light passes through the eyelids.
The most basic approach to meditation is to relax, let go, and do nothing. Surrender to the moment and watch yourself as a silent witness. If thoughts come to mind, then observe the thoughts without adding to them by your active participation. Be a detached and passive observer and simply feel your most basic fundamental being. This inherently immense entity has been called "the ground of being."
http://home.att.net/~meditation/MeditationHandbook.html
