Tea Guy is starting to realize that the topic of Pu erh tea is a rather large one. It's not something that I've really delved into much thus far, though I recently received some Pu erh from Adagio Teas that I'll be reviewing soon. Prior to that I'd tasted Pu erh exactly once in my life - at the Bubble House, in Philadelphia.
For a little more info about Pu erh check out a pair of articles I ran across recently. The first appears to be from a publication put out by the Hong Kong Trade Development Council and the other is from the Toronto Globe and Mail.
Another good resource would be Pu-erh.net, a Web site devoted to the study of, well, you guessed it.
Now, about that spelling...