This article explains what you need to do to obtain medical marijuana in 13 different states that have passed medical marijuana laws. The need to get a permit and the requirements necessary to qualify for medical cannabis vary state-by-state.
http://www.examiner.com/x-17593-NORML-Examiner~y2009m8d9-How-to-get-a-medical-marijuana-permit
http://www.examiner.com/x-17593-NORML-Examiner~y2009m8d9-How-to-get-a-medical-marijuana-permit