I have just started learning piano and my piano teacher told me to buy this book. I have to say, out of the several beginner's books that I have this one is the most sparse in teaching and it's disappointing because of it.
Each time a concept is introduced it is a simple few sentences explaining it followed by a song. This doesn't reinforce the new concept for a beginner and you end up blindly playing along to songs. Thankfully, I had a teacher that could explain the concepts a bit more each time we arrived at a new section. I would recommend Alfred's All in One adult course over this book simply because of the amount of reinforced learning it gives comparatively.
The song selection is not bad and by the end of it you will be able to play a few well known songs but don't expect them to sound too close to the original (looking at you, Singing in the Rain).
Overall, this book is fine if you are going through it with a teacher but there are many better ones if you are not.