Columbia University’s East Asian Institute maintains an excellent site for educators. It covers topics in China, Japan, Korea, and Vietnam. Click on China and primary sources and you’ll find topics divided by period beginning with oracle bones and then moving to selections from the Confucian Analects to sayings of Chairman Mao in the 20th century. The selections print out in pdf and include questions about the sources.
The University also maintains a site on Asian art with links to exhibits about specific Asian topics. For example, you can find a lot of art material on the Silk Road and on the different Asian religions. You can search by time period, country, and subject. Both site are great resources to use during the year.