We found this book to be the most helpful of several on Disneyland (DL), including the Official Guide.
It is far more comprehensive, and contains much more than the short official versions of DL rides and attractions. It rates each ride by age group, so you know what is most attractive and least, depending in your party's composition, and does not hesitate to reprint dissenting opinions they've received from their readers when helpful, which really impressed me about their honesty and openness.
The main gripe about this book is that it tells the truth. DL can be very busy and simply wondering about and "exploring" will likely reduce greatly the number of rides you can get to. That's not the author's fault. We followed a version of their plan modified to our needs and covered far more of DL in 6 hours with three toddlers than I ever expected we could.
The book contains a lot of advice geared toward those with very young children, which was very helpful. A couple hours skimming this on the plane provided a great deal of insight that made our 3.5 year old son's first trip to Disney a memorable, happy experience, when it could have been anything but.