Can someone please explain to me the process of applying to a medical school...

...(i.e. Harvard)? I'm doing research for a book I'm writing. So if you can take the time to help me it would be much appreciated:

What is the process for applying to a school like Harvard and how does that all begin (starting from your last years of high school)? A rough time line would be extremely helpful (like, around what time you apply, take certain tests, send in your application, when you would get an acceptance letter, go for an interview etc.).

As detailed as possible please. Thank you so much in advance.