I received a digital Advanced Readers Copy from Netgalley and all opinions are my own.
I think this would have helped me a few years ago when I was figuring myself out. 
This isn't a book that can tell you yes you are trans or non binary but it'll explain some of the concepts and will hopefully make you a bit less stressed about it all.
I like how the information wasn't just a huge block of text and was broken up with puzzles and activities as well as it telling you exactly what you were going to learn at the beginning of each chapter. And recaps at the end of the chapter too we're helpful. 
One thing I found a bit odd was how the language seemed to yoyo from kids level language to harder to understand terms and concepts. Yes gender is hard to put in simple terms sometimes but the language used just didn't feel consistent. There were several metaphors and figures of speech that didn't really work too.
Over all I'd recommend it to younger readers who want to learn more about gender.