My favourite of his (Fyodor's, guy behind nmap) conference appearances https://www.youtube.com/watch?v=ZMG0e7byPvo Scanning the Internet apparently can raise some eyebrows ;)

Should be general knowledge, but for all who don't know: http://www.sectools.org and http://seclists.org/ are valuable resources!

Funny Side Note: nmap is one of the most widely used "real hacker tools" in movies https://nmap.org/movies/