I was back and forth on this book a few times, but it's a pretty good source for new actors. Cannon breaks down the Stanislavski/Meisner method of creating a character in a series of easy to understand exercises.
On the flip side, she suggests a lot of techniques that I completely disagree with. She focuses too much on using personal memory to create emotion, along with promoting the use of objects from your past. For example, if you are supposed to be upset in a scene, she recommends you find an object, such as a love letter from an ex, that makes you feel upset.
This is problematic in several ways. Objects lose their power over time, something that makes you upset now won't necessarily do the job after a few uses, at which point you'll have to find another object. What happens when you run out of objects? You'll have grown to rely on them to create the emotion for you instead of learning how to do it yourself. You'll never grow as an actor as long as you use crutches like this.
She also waxes lyrical about the benefits of going to drama school, dedicating an entire chapter to it at the beginning. I can understand why, but starting with that might put off older actors who don't feel like they have that option. Rather than being inclusive of actors of all ages and situations, it limits the target audience to very young people. If you can get past this though, there is a wealth of information to be found.
One of the best things about this book is how easy it is to read, and how simple the instructions are to follow. It's great for anyone starting out.