In Mac Power Users episode 230, The Power of PDFs, David and I were joined by attorney Ernie Stevenson to talk about how PDFs can be used for more than just viewing documents. Ernie mentioned in that episode he was releasing a new book, PDF Essential for lawyers. The book is now available and he's offering special introductory price of $4.97 for Mac Power Users listeners if you use this link.
The book is designed for lawyers, paralegals, legal secretaries, law students, and anyone in the legal profession who wants to improve their PDF handling skills, though the information could really be applicable to any field.
By the way, Jeff Richardson of iPhone JD has a nice review of the book, and the MPU episode.