I don't think there is an accurate book. They all have mistakes.
Paul Herds Challenger and Barracuda book is about the best there is. But there are a lot of mistakes in there to. However the mistakes tend to be in the minor details. It is still a good guide.
Your best source is message boards like this one. Moparts is good to if you can be bothered to sort through the 20 conflicting answers to find the right one.
http://www.cuda-challenger.com is a good site with more traffic than mine here.