This is an ideal book to have for reference.
I can't imagine starting at the beginning and working your way through it - though it looks like some people have. But if you have it handy, it will save you a lot of work if you have a reasonable size environment to manage.
Most things seem to have been covered in detail, and if not, then there is usually something there to get you started.
If you want to learn PowerCli then this won't be for you, but if you've got a basic grasp, then this will be a really handy reference.