Need help from your enlightened minds

I didn't know a better category for this. But the main question is How do you take an interview?I am a college student and I want to take an interview of -- for example a doctor who has specialized as an Orthopedic surgeon -- how do I prepare to interview them on their field of expertise? Like, of course noting down questions and all but then anything extra? How do I ask important questions, what should I prepare --- I should give them a copy of the questions I will ask right? 

I have a little idea but anyone with experience in interviewing people -- help ! I want to make the best out of it!!