I have nothing altogether bad to say about this book, I use it for reference once in a while, and it really is excellent at going over arrays for beginners. However, for total beginners (especially if you haven't worked with other scripting languages) there are much better books. I myself would recommend Julie C. Meloni's "PHP, MySQL and Apache" Sams Teach Yourself PHP, MySQL and Apache All in One (4th Edition) instead, for beginners: its a much easier read. For reference, it exceeds this book's usefulness. I only have the second edition of Meloni's, but I would hope the 4th to be as good if not better.
O'Reilly has really been going down hill over the past 10 years. Kind of depressing to see.
Granted this book has no extraneous subject matter (like MySQL or Apache), and like I said.. I DO USE it for reference once in a while. However, I usually just end up grabbing a different one instead.
I personally prefer Python for toolscripts, but PHP is still king if you are doing web-based applications, IMHO.