Kiss Bow or Shake hands is a wonderful book and topic that can be found on the web that will help with culture issues.
I have been to Suzhou China (approx 1.5 hrs drive from Shanghai) 6 times for my company and I love every minute of every trip!
As far as safety, just be wise don't flash money etc.. use all the same common sense that you would if you were traveling within any foreign country.
TAKE YOUR OWN TOILET PAPER!!!!!!!!! and always have it with you, we call it our "visa" because you don't leave home with out it! The small kleenex pocket packs are great. No western toilets, you will have to over come this in your mind first and then it is easy from then on out. I am the master of the squatty potty now
I don't mean to get too graphic here
but just remember the closer you are to that ceramic hole in the ground the better, don't try and pretend there is a seat and there isn't.
Food... when in Rome...... if you are not a picky eater then go for it! I too take cheese and crackers and cup of noodles for back up. But because I was willing to try just about anything my coworkers and I seemed to bond quicker than others who wouldn't. If after I tried something and I didn't like it they had no problem with me telling them that I didn't like it.
Jet lag, I always try to stay up as long as I can the night before my flight, by the time I finally get on the plane and in my seat I am ready to sleep. If I need help to enduce the sleep tylenol PM works for me. The neck pillows in the airport are worth every penny!
Don't forget to have fun!!! The Chinese people I have worked with over there are gracious hosts. On the weekends they always planned at least one sight seeing day, and 5000 years of history provides for some very cool sight seeing.
Good luck, safe trip, and enjoy!!