Most people take 3-4 months to study for the MCAT. Depending on your time commitments, that should be what you're shooting for. Any longer isn't too efficient and any shorter would require full-time work (and risk burnout). If you opt for a course, leave 3-4 weeks between the end of your course and your test date.
As for prep courses, most here self-study. Berkeley Review only offers courses in select areas (mostly in CA). Kaplan, Princeton Review and Examkrackers are all over and you'll get a bunch of opinions. Really, you can't go wrong with any of them as long as you commit.
Personally, I've seen:
1) Kaplan- All course materials. Their online stuff is superb.
2) Princeton Review- Only the books they give you with the course. Very, very good. Don't know about anything else.
3) Examkrackers- No personal experience but friends haven't had great experiences.
The problem with all courses is that it's very hit or miss depending on the quality of your instructor. Sure, they are all smart (and have a 90%+ percentile score) but that doesn't equate teaching ability.. and despite training, some people just don't have it.
If you're going to self-study, I go pretty in-depth in the book reviews and how to set up your own study schedule in this link:
http://forums.studentdoctor.net/thr...he-mcat-study-plan-picking-resources.1045943/
Sn2ed also has a very popular self-study plan that's stickied on this board. I talk about all the books he recommends and would suggest reading that thread as well.