Nmap from an Ethical Hacker's View

The first of two articles, this describes
"Nmap from the viewpoint of a hacker and at the same time give a clear, step-by-step method of attaining a good level of proficiency. After completing this 2 Part Series and having practiced the techniques described, one should not only be able to sit at a "roundtable" discussion with advanced security professionals and "hold their own" in a discussion concerning Nmap, but also utilize this great tool in their own network."

http://www.ethicalhacker.net/content/view/155/1/