Since this will be arranged it will be less traumatic than if it it was an emergency. Ask if you can call the private hospital and talk to a nurse there. He/she can walk you though their program and tell you what you should pack. One thing I've found helpful is to take a notebook for journaling, it will need to be a non spiral note book though. After the first day it will get better, it's best if you can ask to go in at the beginning of the week. Like a Sunday or Monday. Going in on Sunday gives you time to adjust and be less anxious and help you get the most out of the stay.