This book provides a comprehensive introduction to X-ray and gamma-ray astronomy. The first part discusses the basic theoretical and observational topics related to black hole astrophysics; the optics and the detectors employed in X-ray and gamma-ray astronomy; and past, present, and future X-ray and gamma-ray missions. The second part then describes data reduction and analysis, the statistics used in X-ray and gamma-ray astronomy, and demonstrates how to write a successful proposal and a scientific paper. Data reduction in connection with specific X-ray and gamma-ray missions is covered in the appendices. Presenting the state of the art in X-ray and gamma-ray astronomy, this is both a valuable textbook for students and an important reference resource for researchers in the field.