I did a six year accelerated program out of high school so most of my info won't be that relevant. But my sister is applying this year and I talk to her quite a bit.
I suppose key pieces of info:
AAMC calculates your GPA in two parts:
-science GPA
-regular GPA
Science GPA is pretty important and I believe the minimum at most schools is a 3.5. But that will vary depending on where you went to school, ie if you went to a competitive school the med school you're applying to will be a bit more lenient (since it's obviously harder to get better grades). If you have time you can fluff up your science GPA with side research, etc.
The highly competitive schools don't do rolling admission. The SUNY schools do rolling admission so it's best to apply as early as possible.
It's a ton of work applying and getting in; it is a super competitive field. Be prepared.