I am starting in the PICU at JHH this March, so I can tell you a little about my experience when I interviewed...
I first met with HR and discussed basics, benefits, etc. After that I was scheduled to meet with the manager for about an hour... I was terrified!! I didn't know what to expect at all--but she was very welcoming. Many of the questions revolved around experiences with conflict and challenges and your goals that you have for your life and professional career. Just be yourself!! I then spent 4 hours doing "share time" with the PICU nurses. One of the things I loved most about the unit was how welcoming every nurse was. I got to talk with almost every nurse and I got a pretty good idea of the patient acuity and the feel of the unit. When I talked with the nurses I asked mostly about what the orientation was like for them, how they got familiar with the PICU, the learning curve, etc.
Just try to relax and go with the flow! Be yourself and don't be afraid to toot your own horn (as my leadership prof would always say).
Good luck & maybe I'll see you there