here is my list as far as i remember from my interviews in no particular order, i think you should prepare answers for these
1) tell me about yourself
2) strengths and weaknesses
2b) example of one of these strengths or weaknesses and if weakness what did you learn from that event
3) why choose IM
4) why choose our program/what attracted your interest to our program
4b) do you know anyone at this program (previous/current attending/resident)
5) career goals (fellowship, general IM)
6) any past research or research interests
7) (if from far away) why choose this city/state/region, or (if close by) why stay around
8) takes a quote from letter or your statement and asks about it
9) gives you a simple case and asks you to go through it as if it were morning report (old lady with cough, old guy with chest pain) (only happened to me once)
and 10) do you have questions for me? you should really prepare some responses for this one, this is important if you have some things you want to clear up, and it also takes time for them to respond in case you feel like you don't have anything left to say, it also shows some interest, especially if your questions seem thought out and researched, don't spend too much time with this one though, if you have barely talked about yourself yet
11) are not supposed to ask about children/childbearing/family-specific questions unless you brought it up or it's in your application
other tips: dress appropriately, don't make stupid comments at the dinner or anywhere during your visit, don't appear uninterested or like a douche, be polite, good eye contact, don't make a joke that might backfire on you, try to make the interactions feel conversational and casual but respectful, they want to get a feeling that you will be a cool person to add to the program's roster, some people bring notepads etc but some don't, i brought frieda printouts to compare with what the chiefs or PD's said in their presentations, i also brought program specific questions in the notes so i wouldn't forget to ask, get some contact info from current residents/interns if you want more info later, talk to more than one resident/intern because everyone has different opinions, it's really hard to get a good impression of the program from a brief tour and a couple presentations but try your best to observe what goes on around you at your visit
it's normal to be nervous at your interviews, it gets a little easier as you get more done