I study hat making and historic costume. This book is amazing. Buy it without further thought. There are basic easy patterns for all the main hat styles for centuries. Not massive detail but you can get that elsewhere. This saves a lot of messing about.
Get this book without a doubt if you are sewing in a technical way or wanting to do tailoring. It describes everything in an easy to understand way and I think people who don't know much about sewing would be able to follow it too.
Easy to follow with little sewing knowledge though you might want to put it hand in hand with a basic how to sew book and 'Home Sewing Couture Techniques' book if you don't know what you are doing though I would recommend the latter anyway to anyone who needs this book too.
This book has basically everything that you need to tailor a suit and associated items.