While this book is an important reference for Nmap, it isn't the only one. The Nmap web page at http://nmap.org is not just for downloads. It also provides substantial documentation from Nmap developers and third parties. For example, you can find the Nmap Reference Guide translated into a dozen languages there. Other books, videos, and articles covering Nmap are also available.
The official web site for this book is http://nmap.org/book/. Go there for errata, updates, and many sample chapters.
Any serious Nmap user should subscribe to the nmap-hackers mailing list
for announcements about Nmap and Insecure.Org. Traffic is very light
(about six posts per year) because it is reserved for only
the most important announcements. Developers and particularly devoted
users can also subscribe to the nmap-dev mailing list.
much higher (hundreds of posts per month), but it is a
great place to learn about and try new features before they are
released and to pick up tips from advanced users. Subscription
information and archives for both lists are available at http://seclists.org.
While Nmap can be useful, it won't solve all of your security
problems. Every few years I do a survey of thousands of Nmap users to
determine what other tools they like. The list is posted at http://sectools.org, which has become one of my most popular
web sites. Read through the list and you are sure to find many gems
you had never even heard of. Most of the tools are free and open