For clarity regarding "Celadon" - this is a Western trade name, only referring to the color of the cloths, worn by an actor in a well known French theater play during the 18th century.
From a Western point of view, this name now refers specifically to the Greenwares from the Longquan kilns in Zhejiang. Those were special in such a way that they were - and still are - made with a grayish white body and a thick greenish glaze which got its special character from being distinctively underfired and having reached their top temperature very slowly. For more on these technical aspects, please see "Celadon Blues" by Robert Tichane.
If the same ware had been fired differently they would have ended up with a much clearer, sugary and more clearly green color. This feature makes the Longquan "Celadon" somewhat special and gives them a soft touch.
From an Eastern point of view there is no important difference between a Longquan "Celadon" and most other greenish and gray-greenish wares from most areas in China. Let alone they are most common in the southern provinces of Zhejiang, Fujian and Guandong. From a still Eastern point of view anything with a greenish glaze could therefore be called "Celadon color". We could therefore find pottery in Zhejiang from as far back as Eastern Han described as "Celadon" by the Chinese scholars.
An arguable claim would be to say that the production of what Westerners mean by "Celadon", started during the Song dynasty. A good reason for this, is that the subdued hue of the Celadon glaze is very typical for the Song neo-confucian style.
For a latest date for Celadons, there are none. There were a drop in the quality by the end of the Ming dynasty, but the production continued and is still going on, and you could probably go out an buy a brand new "Celadon" flower pot in any Chinese porcelain emporium through-out the world today.
As for literature one of the classics are "Sung Porcelain & Stoneware" by Basil Gray (from the British scholarly point of view where everything is clearly defined). Among Swedish books I would like to mention "Sung Shards" by Nils Palmgren (an exciting personal account) and "Sung Ceramic Designs" by Jan Wirgin, (which is his Doctor's thesis). One of the best most up to date modern books, are the "Green Wares from Zhejiang" published by the University of Hong Kong (of the serious modern Chinese typ).