Key books in Taoism
Tao Te Ching
The key book of Taoism was compiled around the 3rd century BCE. It's called the Tao Te Ching (Dao De Jing or Daode Jing) - The Way and Its Power, and is also known as the Lao-tzu.
This short book of around 5,000 Chinese characters is divided into 81 brief chapters filled with short, enigmatic paragraphs of advice on life, and poetic descriptions of the nature of the universe.
Taoists regard the Tao Te Ching as the essential guide to living a full spiritual and ethical life.
No one person wrote the Tao Te Ching. Although elementary textbooks usually say it was written by Lao Tzu (Laozi) this is untrue. The book is probably a collection of the proverbs and sayings of many anonymous people over a long period of time.
The earliest Western version of the Tao Te Ching was a Latin translation made by the Jesuits in the late 18th century.
Chuang-tzu
Another important book is the Chuang-tzu. Although this was published after the Tao Te Ching, its compilation began earlier. Like the Tao Te Ching it is a collection of the wisdom of many different people.
The thinking that led to the Tao Te Ching was probably influenced by an older book called the Nei yeh. This includes early writings on some key Taoist ideas, particularly ch'i, although some of the ideas differ from their later Taoist form.
The Art of War
There are many other books in the Taoist canon, but one well-known outside Taoism is The Art of War by Sun Tsu, one of the earliest and greatest studies of military strategy, which is explicitly and thoroughly Taoist in its approach to the subject, and which is still read and appreciated by soldiers of all cultures.