There are so many point that are important that I will have to be selective. I will mention only the most important. I suggest that if you want to do business that you do a good amount of research on Chinese etiquette. It is very different than America. Hence, there is a lot to learn. I will put in bold some important words to remember.
First, age matters. Always show respect to your elders. For example, if you enter into a room, make sure that you greet the oldest person in the room first. Also in social interactions, defer to the older person. In meeting, it is typical only senior members speak.
Second, relationships matter intensely. American can do business on a formal level without a preexisting relationship. In China, relationships are the basis for business. Therefore, you will need some history with the Chinese, or you will need a introduction from an intermediary.
Third, the group is more important than the individual. Keep this in mind and try not to stand out too much by exerting your individuality. Keep in mind you represent your company.
Fourth, never be late. Punctuality is consider a virtue in Chinese culture. And when you arrive wait to be seated. There is a unspoken seating arrangement.
Fifth, if ever invited to a dinner, go at all costs. It is impolite to refuse a dinner at person's house. And be sure to read a little manual about eating etiquette.