By incorporating extensive student input and innovative teaching methodologies, this book aims to make the process of learning quantum field theory easier, and thus more rapid, profound, and efficient, for both students and instructors. Comprehensive explanations are favored over conciseness, every step in derivations is included, and 'big picture' overviews are provided throughout. Typical student responses indicate how well the text achieves its aim. ''[This] book ... makes quantum field theory much easier to understand!'' ''Thanks for ... making quantum field theory clearer!'' ''Awesome. .. approach and presentation .. just awesome !!! ''Best presentation of QFT I have ever seen .... marvelous!!!. '' transforms learning QFT from being a hazardous endeavor to actually being an enjoyable thing to do.'' ''Great job .. extremely clear ... guided me through many ambiguities .. I wasn't able to work out with any other book.'' ..''truly special... extraordinary text. For me, ... a big relief .. finding [this] text.'' The book focuses on the canonical quantization approach, but also provides an introductory chapter on path integrals. It covers fundamental principles of quantum field theory, then develops quantum electrodynamics in depth. The second edition incorporates suggestions from readers to make certain sections even clearer and easier to understand. See the first few chapters at www.quantumfieldtheory.info.