This third book in the Learn to Play Go
series, which is supposed to bring you to about the 10-12 kyu level, I did not find as useful as the first two books. We're now at the level where you need to learn practical strategy and tactics, and much of the book is a recitation of terms and some illustration of basic principles we already know. The most useful parts were probably the example games, but you really need to study a lot of those to get much out of them.
So, am I a 10-12 kyu player yet? Well, no, but you have to play
a lot to gain the experience necessary to make use of the teachings of a book. I would say the first two books in this series are excellent, the third is worthwhile. Time to move on to book four and see if it will unleash my inner Hikaru.