As a teacher of drama to many low-income, urban, and "difficult" adolescents, this is the book that I find most useful, alive, and inspiring! Simply wonderful for anyone trying to bring the best out of young actors!
This book is great to use in the classroom. It is full of ideas and the students will love it. They get to play and act out things while learning, it's a great change of pace. Spolin's ideas and thoughts are very helpful. Get this book, your students will thank you!
Spolin is a well-recognized authority on matters of this sort -- improvisation and classroom games. One of my theater professors uses this as the textbook for her class on using theater in the classroom. It's popular enough to be one of the safer buys if you're looking for this sort of thing.