Each program is different, but I will try to answer you questions as best I can.
Most programs want to find out about you, not just your grades. They want you to be happy, and then generally they are happy. If they give you the "third degree", it may not be the place for you.
1. How best should I prepare?
Be well rested, dress well, and read as much as you can about the program so you can ask questions to find out if you want the program - ask the residents and during your interview. Some programs wonder why you ask a question, if they all ready sent the information to you... Knowing about them shows your interest.
2. What do they look for in selecting ideal candidates?
Here, as mentioned before, each program is different. Everyone wants a well rounded, well qualified person.
We look at who you are, what you have done... research, volunteer work, did you have to work to pay tuition. We look to blend a team of residents together, to work as a team, to learn from each other as well as from. We also are able to take people from different places in the class standings. This year, we had only 8 residents but from FIVE (5) dental schools.
3. Any dos and donts?
Don't look impatient, try to be relaxed. Don't chew gum, be honest, ask questions, don't try to hide anything (often programs know people from your school), Learn about the area if possible.
4. How many schools is a good number to apply to?
This will vary from student to student. If you are #1 in your class, have high 90s on your boards (national boards in a few years may go to pass/fail), have the best personality, etc.... any place you apply MAY take you... but, apply to more. There is nothing that is a sure thing - the program may close, they may have already promised the spots to relatives etc, or you may seem too cocky only applying to 1 program.
I would apply to all you are interested in, and may try some other places... you do not have to except an interview. The more places you apply, the more places that will have your name if you need to go post match.
These are just some ideas. If you wish you can call me on my cell 302-530-6788, or see me at the greater NY meeting Sunday morning at the resident fair.
Robert N. Arm, DMD
Vice Chair, Dept. of Oral&Maxillofacial Surgery and Hospital Dentistry
Program Director, General Practice Dentistry Residency Program
Christiana Care Health Services
Wilmington, DE 19801
cell - (302) 530-6788