I take two suitcases, one for my clothes and personal things, and the other for books and teaching materials. Textbooks for teaching English are usually pretty blah, so you'll be relying on other materials to dress up your lessons, especially if you will be teaching specialty forms of English.

Most all hygiene products seem available in cities, but sometimes for a pretty penny if you need imported products. But dental floss and deodorant are sometimes hard to find. Clothes in all styles and patterns are widely available at good quality, but if you are unusually tall or "heavy" you might have a hard time finding something that will fit properly.

Laptops are iffy. China is the land of computer viruses and spyware.

Take a few pictures of your family and hometown. They're good for making friends and breaking the ice.

Patience and level headedness.