Congratulations on your child’s admission! I have been through this a couple of times - and the #1 thing to remember is to RELAX. NU & your kid has got this covered, and your son will do just fine, even if you are not there! However, follow the link below and a lot of your questions will be answered:
http://www.northwestern.edu/orientation/about-us/faq/wildcat-welcome/index.html#!