Took the Kaplan MCAT prep course. Definately worth it.
Knew I wanted to go to MCG, so I did early decision. All GA residents get a secondary app, and MCG interviews the ED candidates in August. Get there early, they have breakfast food. Do your first of two interviews, then a tour, then lunch (again, they supply the food). After lunch, one more interview and you're free to go home and angst about getting in. The whole day is very relaxed, not high pressure. Nobody actually came out and asked me why I want to be a doctor. The first interview was with a geneticist PhD who talked with me about languages and cultures, and where I wanted to practice medicine. The second one was the pathologist who works in their blood bank. He asked a lot of good questions, along the line of 'what did you learn working in submarines that'll make you a better doctor'. You can probably insert whatever significant extracurricular activity you have on your app for the 'submarines' part. Both interviewers were friendly and zero-stress, and let me ask them about their specialties and were very forthcoming.
The tour was pretty cool, it was led by 2 students, and we covered pretty much the whole campus. Wear comfortable shoes!!!!
I was nervous about my grades, being that they were below the avg. The interviewers told me that if you get to interviews, they've already looked at grades and are cool with them. They want to see if your mindset fits the school's, or something to that effect.