"Confucianism, Taoism, and Buddhism are one" (Song Dynasty)
The first major philosopher who lived in China was Lao Tsu (if he really existed), about 600 BC, under the Eastern Zhou dynasty. Lao Tsu founded the philosophy of Taoism, which said that people should try to live in harmony with the universe, rather than fighting it. Instead of living by rigid rules and laws, people should try to work with the natural way of the world, and in this way their lives would be easier and happier.
Not long after Lao Tsu began teaching Taoist ideas, another philosopher named Confucius came along to disagree with him. Confucius, who lived about 550 BC, also under the Eastern Zhou dynasty, taught that people should recognize their responsibilities to the larger society, and work to uphold the laws and customs of their society. If everyone was a good citizen, the whole community would benefit and everyone would be happier.
You can see that these two ideas conflict with each other. Yet both Taoism and Confucianism were popular all over China for the next two thousand years, and they are still both popular today.
Confucius: The Golden Rule, by Russell Freedman (2002). - some biography, and some philosophy. Good reviews.
The Life and Times of Confucius, by Kathleen Tracy (2004). .
One World, Many Religions: The Ways We Worship, by Mary Pope Osborne (1996). .