3 answers
Ryan’s Answer
In my experience, there isn't a single "best" school in order to gain acceptance into in post-doctoral program. Though an argument could be made that if you have your heart set on going to Harvard Medical School, getting into Harvard's undergraduate program would be beneficial.
However, after having gone a long way to get into veterinary school, I've found that attending an undergraduate program in a school, location/setting that you enjoy would give you the best chance on being happy and thus making great grades just a bit easier. For instance if you want to attend medical school at Stanford, but dislike the culture associated w/ the Silicon Valley, it will be hard to maintain a good attitude on a daily basis. Basically it will feel more like "work."
And furthermore, I wouldn't get to hung up on attending a certain medical school, after all do you know what a graduate of Harvard Medical School and one from Texas Tech University Health Science Center have in common? They are both called Dr. when the graduate.
Richard’s Answer
Pick a college that suits your personality you so you don't mind devoting a majority of your hours to studying. You will need to get good grades in college in order to apply for medical school. At the medical school I attended, the average GPA is reported to be 3.85, so even one or two B's can hurt your chances of acceptance.
If you plan on doing medical research and want to go to a top medical school, it may help your chance of admission to go to a top college such as Harvard, Yale, Princeton or Stanford.
However these schools may place a financial strain on you and your family. If that is the case consider a less expensive community college followed by a state university to save money. You will have to pay for medical school too, so saving money at the beginning is a good choice!