After promising you a book on Nmap for years, I'm delighted to finally
announce the release of Nmap Network Scanning!  It contains everything
I've learned about network scanning from more than a decade of Nmap
development, plus some bad jokes and (over Time Warner's written
objections) pictures of Trinity hacking the Matrix .  Here is the
abstract:

  Nmap Network Scanning is the official guide to the Nmap Security
  Scanner, a free and open source utility used by millions of people
  for network discovery, administration, and security auditing. From
  explaining port scanning basics for novices to detailing low-level
  packet crafting methods used by advanced hackers, this book by
  Nmap's original author suits all levels of security and networking
  professionals. The reference guide documents every Nmap feature and
  option, while the remainder demonstrates how to apply them to
  quickly solve real-world tasks. Examples and diagrams show actual
  communication on the wire. Topics include subverting firewalls and
  intrusion detection systems, optimizing Nmap performance, and
  automating common networking tasks with the Nmap Scripting Engine.