I actually just picked up Dawson's book also I'm looking forward to reading it. I know it comes highly recommended.
Along with that I got John Kehoe's Mind Power book. I started it last night it's a great read albeit quick. I do feel like it's a bit silly though that he supposedly went in to the woods for three years to discover what was already written in Think and Grow Rich. I'm about a third of the way through and while I really like the way it's laid out and explained, It's nothing I haven't heard from Napoleon Hill, Tony Robbins, Brian Tracy, et al.
That said, I used powers I've learned from the authors I mentioned last weekend when I bought a new car. Not negotiation in particular, but doing away with self-limiting beliefs. The night before going to look at the car I told myself that I was a great negotiator. I pictured myself saying certain things and acting "as if" I was not to be trifled with. Wouldn't you know it, I owned the poor kid on the other side of the table. Eventually his manager came in with the numbers I wanted and said that I was "beating up his guy". I felt great and it makes me love my new car even more!
