Related link: http://www.insecuremagazine.com/INSECURE-Mag-3.pdf
INSECURE is a fun [relatively] new security magazine, distributed as PDF. I found some interesting bits in the latest - 3rd - issue, that just came out. Those include articles on extending nmap service detection as well as some higher-level pieces.
I find it curious that the magazine manages to pack good articles for very different types of people, from CISOs to “real” practitioners :-)


(plug) the nmap section is an excert from Network Security Tools
http://www.oreilly.com/catalog/networkst