This book provides a new alternative introduction to the theory of modules and rings that is largely independent of the author's earlier graduate text, A First Course in Noncommutative Rings (GTM 131). Developed from the author's lectures given over the years at Berkeley, this text is ideally suited for use in graduate courses and seminars, as well as for self-study and general reference. Focusing on some of the most central topics in modules and rings, the author efficiently introduces the reader to a wealth of basic and useful ideas without the hindrance of heavy machinery or undue abstractions.