China is a vast country and it's a challenge to get from one city to the next. While travelling in the cities and the countryside the behaviour of the locals will shock and may even irritate you, like smoking in elevators and spitting and/or littering in public places. It's a different culture after all and you will be a guest in their country. Losing your cool will accomplish nothing whatsoever, so remember to smile. Saving face is of paramount importance to the Chinese.
It's likely you'll begin your trip in Beijing or Shanghai, both of which have embraced consumerism. Beijing's boulevards are wide and for good reason. Thousands upon thousands of bicycles, not to mention a large complement of cars, clog every inch of available space. For a nice taste of recent Chinese history a good place to begin is Tian'anmen Square, the largest urban square in the world. The father of modern China, Mao Zedong, is encased inside a mausoleum on the southern end of the square. Look to the north and you'll see a big portrait of him, watching over locals and foreigners alike even long after his death in 1976.
Learn some Chinese before you arrive, because it will make communication easier. Don't expect English to be spoken at all outside the larger cities. Mandarin is tricky at first but once you get the hang of the tonal system it's a snap. There are no less than fifty-five ethnic minorities in China, and they each speak their own unique dialect of Chinese. Some of the more prominent groups are the Miao, Naxi, Yi, Uyghurs and Tibetans.
Although the country is modernizing at an astonishing pace, behind the tall, gleaming office towers and fashionably dressed teenagers things are still quite traditional. In other words, China is westernized but not western. Elderly men and women still walk the streets wearing the dark blue and gray Mao suits which were the norm back in the 1970s. Elements of the Cultural Revolution still remain, such as the disdain of cultural relics and the absence of any major religions. Be prepared to pay high prices for basic necessities in Beijing and Shanghai. The further west one goes, the cheaper things will be