An excellent textbook for the growing field of networks, an interdisciplinary field with myriad applications in computer science, sociology, economics, physics, biology, and many other realms of scientific endeavor.
Newman's book consists of five parts of increasing complexity, from an informative description of different types of networks to the study of dynamic processes on networks. His writing style is engaging, witty, clear, and instructive (and mathematically rigorous when needed).
Being highly self-contained, computer scientists and professionals from other fields can benefit from it.
PS: Several recent textbooks have tried to organize what is currently known about networks, their structure, and behavior, from different points of view (e.g. Easley & Kleinberg's
Networks, Crowds, and Markets). Newman adds a new perspective to this collection of textbooks - that of a physicist with a keen eye on networks.