Personally (and I know there are many people who will disagree), I don't recommend any study of Traditional Chinese Medicine at all to facilitate your study of pressure points, with the exception of finding a text that will help you actually locate the pressure points themselves. And I'm saying this as someone who has a professional qualification in Traditional Chinese Medicine.
The main things to learn are simply where and how to hit. I would heartily recommend 'Kyusho Secrets' by Vince Morris. You can get hold of this in the US, UK, Europe or (I believe) from Vince's website.