A more general book is The Science of Parenting... I have found it invaluable, it goes into details explaining the changes in your babies/toddlers/childs brain, and why they have tantrums, and behave the way they do in all sorts of situations, and the best way to go about managing it.
It is not a specific book on discipline though, but it certainly offers a wonderful insight into the workings of our little ones brains and thinking... from newborn to child.