The Classic of Tea

By Lu Yü

Lu Yü was a man who not only appreciated tea, but who appreciated the ritual of tea making. He wrote this book about 760 AD and in it he describes the steps and the importance of proper preparation for making tea.
In this edition, the translator, Francis Ross Carpenter, had added quite a bit of historical information about China, tea, and Lu Yü. This section of the book really adds a lot to the author's original work.
Lu Yü's part of the book has three sections, the first about tea production, the second about the correct utensils used to make tea and the last about tea quality and famous tea drinkers and more.
An excerpt from Lu Yü's book:

The first cup should have a haunting flavor, strange and lasting. There are those who allow it to continue simmering to nourish the elegance and retain the froth even through a first, second and third cup. After the third cup, one should not drink more than a fourth or fifth cup unless he is very thirsty.

Sometimes such items as onion, ginger, jujube fruit, orange peel, dogwood berries or peppermint are boiled along with the tea. Such ingredients may be merely scattered across the top for a glossy effect, or they can be boiled together and the froth drawn off. Drinks like that are no more than the swill of gutters and ditches; still, alas, it is a common practice to make tea that way.

While its recommendations about tea preparation are of little use now, still it serves as a fascinating glimpse into a bygone era and ancient tea culture. Makes for a pretty interesting and charming read.