I studied with James Lewis (in person) and have great respect for him. However, the book on which the PMP Exam is bases, A Guide to the Project Manager's Body of Knowledge (PMBOK) has changed since Dr. Lewis wrote his Fundamentals book.
There are many new things that are different and would lead you to make errors on the PMP Exam.
The Head First PMP book, followed by a thorough examination of the PMBOK may be your best bet.
Many local Project Management Institute Chapters have low cost review sessions for you after you have read these books and done some studying on your own. Check out a local chapter (they have them internationally) at pmi.org.
The book is geared toward passing the PMP exam. It's a PMP prep guide, pure and simple. But a lot of software developers have taken the plunge into project management and decided to go ahead and get certified. If that's something you're interested in doing, then the book is for you.