is a pretty good one I think ( and kind of humorous :0) Once you get the knack of what's going on you really start to appreciate POE. Rocco Caputo told me that he knows of 2 folks working on POE books, but he didn't know when they would be available for public consumption. He said he is too busy to write one. I think a tutorial on this site would be fitting.
It showes you how POE can be used in a non-blocking SSL Client that polls 2 https web pages cooperatively.