The Association of American Medial Colleges recommends that you begin studying for the MCAT exam at least three months in advance of your exam date. Try to set aside at least an hour each day to study without any distractions (cell phones, the Internet, etc.). Choose a time when you are most likely to be focused. For some people, this is in the evening; for others, it may be the morning.
There are numerous books devoted solely to MCAT preparation. "The Official Guide to the MCAT Exam" is available through AAMC.org and provides extensive information about what to expect on the exam. Other reputable MCAT books written by the Princeton Review are available through publisher Web sites such as Randomhouse.com. The practice tests in these books are useful study tools and can gauge your ability to score well on the MCAT.
Study groups allow you to think out loud and share your ideas with other people who are also preparing for the MCAT. People often can explain concepts in a way that books cannot, which can be helpful in understanding difficult material. Study groups can also provide a source of motivation to study and are often more enjoyable than studying by yourself.
No matter how much you study, your brain will function better if you are healthy. Serious test preparation means limiting your alcohol intake in the weeks prior to taking the MCAT. Getting at least seven or eight hours of sleep the night before a test and eating a nutritious breakfast will help ensure your brain is functioning optimally.