Mayo Clinic
Mayo Clinic: Meditation
This site from MayoClinic.com provides great information on meditation. The article is entitled, "Meditation: Calming your mind, body and spirit". Describes what meditation is and how it works, along with giving a list of links.
Other
Meditation Therapy: Brief Instructions for Seated Meditation
A set of instructions for seated Zen meditation.
Other
American Meditation Institute: A Systematic Procedure for Meditation
The American Meditation Institute for Yoga Science & Philosophy provides this step-by-step procedure on how to meditate.