Hacking For Dummies is an excellent introduction to hacking for beginners. 

The media often mistakenly characterize hackers as bored technical geniuses. In truth, most hackers, as the media use the term, are not geniuses; they are simply adept at downloading hacking tools that do all of the dirty work for them. These so-called script kiddies often do not know what they are doing until the damage is done. 

From the perspective of the victimized company, however, it's not really important who is doing the attacking; all that matters is how organizations can protect themselves from myriad attacks and tools. Hacking for Dummies is written on the premise that to catch a hacker, you have to think and behave like one. This is a well-written and engrossing book that helps the reader understand how hackers compromise computer systems and networks. Its clear, easy-to-read style won't intimidate readers unfamiliar with abstruse security terms and concepts. 

The 19 chapters progress from the basics of security to the hardening of an operating system and the hacking of Web applications. While the reader is not expected to have a deep technical background, the book does go into some detail, as it must to provide a hands-on approach. For a high-level theoretical approach to network defense, look elsewhere. This is a down-and-dirty tool for ensuring that the organization's systems and network are secure.