This is a great book that will no doubt help a lot of people. This will be best used and kept as a reference book and is certainly a good book to have in your arsenal, whether or not you're in the entertainment field or looking to go into it.
As someone who is currently most of the way through earning a Bachelor's of Fine Arts in Creative Writing, this is definitely a useful book. I am pleased to have this as not only a reference guide, but to also have in my arsenal.
While this book may not give you every single thing you need to know on how to get published, it will certainly be handy for your journey into publishing and certainly can't hurt. I'd suggest going out there and grabbing this one, no matter where you are on your journey.