Chinese Zen (more properly called Chan) begins with the foundational myth of Bodhidharma’s encounter with the Emperor in the 6th century. Huineng emerged in the 7th century. The long collapse of the Tang dynasty and Confucian persecution of Buddhism mean that many of the figures we read about in kong-ans — Majo (Matsu), Baizhang (Pai Chang/Baek Chang). Huang Baek (Huang Po), Joju (Chaochou), Dong Sahn (Deshan), and so on — lived in difficult times. Buddhism had a resurgence in the Song Dynasty, which is the period in which we now call Zen solidified.

The key Zen texts are compilations of kong-ans. Andy Ferguson’s Zen’s Chinese Heritage, the most complete contemporary introduction to Chinese Chan, presents some of the text of the Record of the Transmission of the Lamp, the defining compilation of biographical information about Chinese Zen masters from the Tang and Song Dynasties. The most significant compilations, however, are shorter anthologies created in the Song Dynasty, specifically for teaching purposes: 

Mumonkan, [the link is to Wikipedia] compiled by Zen Master Mumon, consists of 48 kong-ans, is the defining collection, still in use today. For KUSZ students, Zen Master Seung Sahn’s translation is the most important, but there are many other, more complete translations, such as Robert Aitken Roshi, The Gateless Gate.        

Blue Cliff Record[the link is to Wikipedia] consists of 100 kong-ans. The characteristic Song Dynasty Zen anthology, also very influential, if in places quite obscure. Zen Master Seung Sahn translated the cases only; Thomas Cleary’s translationis the only complete version in English. 

A good overview of the kong-an tradition can be found in Richard Shrobe’s Elegant Failure: A Guide to Zen Koans

Important Chinese ancestors are:

Bodhidharma the first ancestor        

Huineng the sixth ancestor. His Platform Sutra(a.k.a.Sutra of Hui Neng) is a seminal text with many translations. [we should link to more than just Yampolsky]Among the many translations, Philip Yampolsky’s provides an excellent introduction to the legend of Huineng and the significance of the Platform Sutra

Mazu (Ma Jo),whose sayings are collected in Master Ma’s Ordinary Mind. Mazu’s grandteacher was Huineng. His many students (he gave transmission to over a dozen people) include Baizhang and Layman Pang.

Baizhang (Pai Chang/Baek Chang), who created the first set of temple rules and made Chan self-reliant, i.e., not reliant on begging for sustenance (“a day without work is a day without eating”).

Huangbo (Huang Baek) whose writings are collected in The Zen Teachings of Huang Po. Huangbo’s teacher was Baizhang.

Linji the founder of the several Linchi schools (Korean Soen is one; Rinzai Zen is another) whose sayings are collected in the Linchi Record. Linji’s teacher was Huangbo.

Deshan (Duk Sahn)was a contemporary of Linji from a different lineage. (Arcane fact: his ancestry traces to Huineng’s teacher but not to Huineng.)

Yunmen (Un Mun)whose sayings are collected in The Yunmen record. His grandteacher was Deshan.

Dahui whose writings are collected in Swampland Flowers. He lived 200 years after Yunmen, at the time of consolidation of Zen in the Song dynasty. It was Dahui who laid the foundations of what we know as kong-an practice; the great kong-an collections were produced over a time period of a hundred years, beginning when he was alive.

Other important and accessible texts are: 

Xin xin ming, Xin ming and related texts: These are early Zen gathas(traditional Buddhist poems) attributed to Jianzhi Sengcan and Niutou Farong, the third and fourth traditional patriarchs of Chinese Zen. The Xin xin ming has been translated by Stanley Lombardo, as well as many others; the Xin ming has been translated by Jess Row is also available with commentary in Sheng Yen, Song of Mind. 

Shunryu Suzuki,Branching Streams Flow In The Darkness:A translation and commentary on the Tang Dynasty Zen textCantongqiorSandokai, by Shitou Xiqian. Along with theXin xin ming,Cantongqiis one of the most important texts of Chinese Zen.