I took this 15213 course at Carnegie Mellon University last year. This book was one of the required reading material, (the other one was "C Programming Language"). We were lucky enough to have Randal E. Bryant and David R. O'Hallaron as instructors that semester.The book covers almost every fundamental concepts in OS. It does contain a significant amount of information, but the way it's written does not confuse readers nor make them sleepy as some brick textbooks do. Actually it is pretty well written and organized so readers can follow through without much trouble (might need clarification and guidance once in a while). The practice questions after each chapter is excellent material to get a favor of how each little piece works. Lab assignments from the book aim to help readers assembly these pieces into a whole. Labs do require certain degree of time and effort, especially for beginners.Lectures from two authors went extremely well with the book too. I am still feeling glad today that I took the course, which lead me to this book and two excellent instructors.