Hi Quester
An oft-quoted number for MCAT prep is 300. Three hundred hours is a general estimate of the time you'll spend prepping for the test. Depending on your background and target score, that number can fluctuate!
(As a former Kaplan MCAT student, I totally loved my experience and found it really helpful to have the abundance of materials, resources, and direction that they offer. Disclaimer - I teach for them now. If you have the desire and determination, Test Prep Companies can help you immensely!)
Anywho - within that 300 hours, you'll want to complete between 5 and 10 (if not more) practice exams, each taking 5 hours. Plus, you want to review each exam thoroughly and learn from every wrong answer, while looking for patterns between those mistakes that represent faulty thinking or processing overall.
For tackling content areas, check out the following AAMC website:
https://www.aamc.org/students/applying/mcat/preparing/85560/test_sections.html
and identify your weaknesses and strengths. For all your weaknesses, make sure you review the content areas only within the scope of the MCAT while practicing relevant questions that test your ability to think critically at an advanced level.
Many students like to think about MCAT prep as if it is a 4-unit semester course. Dedicate 10-20 hours/week if you can and create both short and long term goals for yourself. Make sure you track your progress - take necessary study breaks - and ramp up your efforts if you don't see the results you want or you hit a plateau.
It all comes down to motivation! (and a lot of organization...)
Also - if you're interested in applying to US allopathic (MD) schools THIS summer, the August administration of the MCAT may be a little late and put you near the bottom of the application pile. You want to apply ASAP with an MCAT score that accurately reflects your abilities
Good luck and have fun!