The Williamson download is good, although you're better off figuring out your own body language and thinking about your own sense of timing than duplicating his little finesses. Actually, the best thing on the top change I've come across recently is this conversation on the top change vs. the double lift between Andrew Musgrave and Tyler Erickson.
http://sleightly.com/blog/2011/03/04/63365-audiolog-tyler-erickson-talks-about-the-dl-and-tc/
It's free, and there's a ton of good information here. Most importantly, it stresses that the top change is not 100% burnable, and it's a mistake to treat it as if it is. It really is about timing and misdirection.