Dave (Immunity, Inc., New York, USA) Aitel & Susan Young 
The Hacker »s Handbook [PDF ebook] 
The Strategy Behind Breaking into and Defending Networks

This handbook reveals those aspects of hacking least understood by network administrators. It analyzes subjects through a hacking/security dichotomy that details hacking maneuvers and defenses in the same context. Chapters are organized around specific components and tasks, providing theoretical background that prepares network defenders for the always-changing tools and techniques of intruders. Part I introduces programming, protocol, and attack concepts. Part II addresses subject areas (protocols, services, technologies, etc.) that may be vulnerable. Part III details consolidation activities that hackers may use following penetration.