As an old and now somewhat crusty marine engineer and offshore mechanical engineer I'm very familiar with machining and tooling. But, that's not to say I know enough to consider myself fully competent and if I can add to my knowledge I will.
Mind you today, the majority of manual machining seems to be with the hobbyists - and I throw myself into that now. Whilst my day job might be offshore construction I like to keep my old skills alive in my own workshop at home.
And I bought this book to help and hopefully learn a bit more. And honestly if you were a complete novice then it would be excellent as an introduction. However, if you already have some skills then most of what is in this book is familiar. And if you have worked in industry then chances are you may have come across some techniques that are not in this book.
Most of all, what is evident, is that this kind of book is less relevant than it used to be. Having discovered that YouTube is more than cat videos and rap, there are some properly good videos made by both professional and amateurs alike that cover all the ground you need to cover and then some.
So, fundamentally I'd consider this book to be a general help but is looking overall a bit old fashioned and less useful than it would have been a few years ago.