I'm working on my solaris 9 certification and I can tell that this is a good book to use. I haven't done any exames yet but I'm going to put all the chances on my side by using the exam cram book so that way I won't come back here and complain about the book!! I've never done any certifications using only 1 book!!during my reading I found few errors but nothing major, still I enjoy reading a book without worring about the errors that's why I give a 4 out or 5 to this book!it's a very good solaris 9 book and I recommand it!