Which process is that?
1) the actual the mechanics of how AMCAS and the subsequent processes work
2) the decision making process of how schools evaluate and decide on applicants.
3) the thought process and crafting the experiences and subsequent narrative of an application
To answer:
1) you should study and know like any other course via the MSAR, applicant guide and myriad of FREE materials from AMCAS (see links in my signature), individual medical schools websites, and the huge amount of other free materials. Of course if you prefer to pay I have very unreasonable rates
2) this is the something you can only know in general terms. The black box of decision making when there are fifty thousand plus applicants submitting hundreds of thousands of individual applications across one hundred and fifty plus medical schools being reviewed by thousands of individual adcom members in of large variety of small-group dynamic settings. I will see that vast majority applicants do not understand the basic conceptual philosophy that an adcom uses to considered your fitness to be a physician. They need to take the concrete activities that you narrate in your application and see what evidence it gives to the attributes, characteristics, and traits that would make you a good physician. And since there are many paths to the many characteristics to be a good physician this question is impossible to give some absolute answer to applicants on how to be a superstar
3) Knowing how to prepare your background and then narrate it on applications is the process that applicants need to address. A medical school application is a coherent, concise, and compelling narrative showing a strong pattern of motivation, commitment and achievement. The mechanics of how to do that I will discuss another time.
I will say that I have seen very few, if any, superstars, in terms of work and activities that would speak for themselves.