I was working full-time during my MCAT prep time, which was terrific.
I didn't take a course. I started prepping about two months prior to the test and went roughly in this order:
- Self-assessment by taking a full-length practice test.
- Reviewed material in an MCAT prep book (I think I used Barron's; it was okay.) Probably a couple of hours, a couple of nights a week.
- Took at least one full-length practice test every weekend. The tests on e-mcat.com are worth every penny! I also used old hard-copy practice tests from a friend who had taken a prep course, as well as the back-of-the-book tests in prep books. Library card FTW.
So that was the first time I took the test. I re-took it three months later (long story; I don't think it was because I prepared poorly) and had more relaxed prep for the re-take. I reviewed only the material where I was really lacking, and took a practice test or two during the 3-4 weeks prior to the test. I also used Kaplan's MCAT 45 prep book-- not because I was aiming for a 45, but because it was concise. It was very helpful in terms of strategy (and thus in confidence-building). Did lots better the second time. I recommend not taking a course if you have the motivation to study on your own. And I recommend not flipping out about it like I did the first time.
Good luck!