The Chinese in 1958 adopted a system of writing their language using the Roman alphabet. It's known as pinyin. The original idea was to eventually do away with characters. However, tradition dies hard, and the idea has been abandoned.
Pinyin is often used on shop fronts, street signs and advertising billboards. Don't expect all Chinese people to be able to use pinyin. However, there are indications that the use of the pinyin system is diminishing.
In the countryside and the smaller towns you may not see a single pinyin sign anywhere, so unless you speak Chinese you'll need a phrasebook with Chinese characters.
Since 1979 all translated texts of Chinese diplomatic documents, as well as Chinese magazines published in foreign languages, have used the pinyin system for spelling names and places, pinyin replaces the old Wade-Giles and Lessing systems of romanising Chinese script. Thus, under pinyin, “Mao Tse-tung” becomes Mao Zedong, “Chou En-lai” becomes Zhou Enlai, and “Peking” becomes Beijing. The name of the country remains as it has been written most often: China in English and German, and Chine in French — in pinyin it’s Zhongguo.