Last month the History Channel aired a segment on their Modern Marvels program on tea. They did a nice job of covering history, and brought out some aspects that are not always covred in many of the books that have been written. In addition, they interviewed a number of people in the industry all the way from a plant manager for Lipton to James Norwood Pratt.
If you are interested in increasing your knowledge about tea history, how it is processed (especially in a tea bag factory), and current trends, I would reccommend finding this video. It can be ordered from The History Channel for $24.95, or found at local libraries, and I am told, Netflix.