This book provides an introduction to quantum information science, the science at the basis of the new quantum revolution of this century. It teaches the reader to build and program a quantum computer and leverage its potential. Aimed at quantum physicists and computer scientists, the book covers several topics, including quantum algorithms, quantum chemistry, and quantum engineering of superconducting qubits. Written by two professionals in the experimental and theoretical fields of quantum information science and containing over 200 figures and 100 exercises with solutions and summaries at the end of each chapter, this book is set to become a new standard in the field.