This was a bit of an odd book for me.
On the positive side of things, it covered the basics of gender identity and transgender well and concisely, first going through exactly what gender is and then going through some important terminology. I also liked that it covered both transgender in children and transgender in adult.
Another good thing about this book was that it covered a few case studies of transgender, including the famous, tragic case of Brandon Teena/Teena Brandon. It is important that young people know about their history and how legislation and awareness came into being.
However, on the flip side, I found it a bit confusing. Not that anything was wrong with its message, just its target audience. On the surface, it seems that the book is aimed at children, with its large text, cute cartoons and bright colours - and the fact it helpfully defines words like 'traditional'. But then the way the text words things seems as though it's aimed at a much older audience - and words such as 'masculine' and 'effeminate' aren't defined (which is odd, because it would seem more appropriate to define those words when talking about gender!). I'm pretty sure this book is aimed at young teenagers (it's a bit like a book you would look at in PSHE), but it really doesn't seem to be written that way.
As I said, however, it is a good book for learning the basics abour transgender and gender identity. There are probably better books out there, but this one is short and straightforward and (importantly) it's very recent. This means it has all the up to date legislation and cultural attitudes, which is important for people growing up with these issues.
All in all, if you want a quick overview of gender identity and transgender issues, this is quite a good place to begin.