How much work should I do to prepare for medical school interviews?

It is up to you how much work you do to prepare however, I would warn you that you can definitely do to much. Prepare to the point where you feel confident answering most questions but in the interviews, one of the things that they are looking for is how you respond to questions under pressure. The other thing to remember with medical school interviews is that you can never prepare an answer to every question; the schools will always find another question to throw at you. I would recommend getting a book that has some questions in it that are commonly asked at medical school interviews and preparing answers to as many of those as possible. I used a book called medical school interviews by Olivier Picard and George Lee. My school also did practice MMIs with us and I would recommend trying to do at least one of these. Medic portal is also an amazing site to use.