The Medical College Admission Test (MCAT), developed and administered by the AAMC, is a standardized, multiple-choice examination created to help medical school admissions offices assess your problem solving, critical thinking, and knowledge of natural, behavioral, and social science concepts and principles.
Taking the MCAT Exam from The Association of American Medical Colleges
e-MCAT Practice: The Official MCAT Practice Site
Sample MCAT Test Questions from Peterson's
MCAT Test Prep from Khan Academy