Hacking is an art and can be used for both offense and defense, for pro-active defense you need to know hacker tactics for securing yourself/organization against hacking, there exists a very thin line of hacker ethics distinguishing between a WhiteHat and a BlackHat hacker, I have always been very curious in learning this dark art for ethical purpose and finally got hold of "The Secret Of Hacking" - Ethical hacking course, unlike other outdated ebooks and basic courses this one is authored by an established Government recognized Indian security company and really packs a punch with all aspects of hacking and securing as promised on the sales page.
The course comes with one printed book and two DVD's having more then 14500 security related tools and 200+ Hacking E-books/Videos, the best part is that you get a lifetime membership with access to an ever growing collection of videos and technical support.