I just finished reading Kevin Mitnick's new book, Ghost in the Wires. This was an amazing read. If you are involved in information security in anyway, I really recommend you (and your boss) read the book. This is not a technical manual on how to do social engineering, if you are looking for that I recommend Kevin's "Art of Deception". Instead this book is Kevin's story on how he used social enginnering to get what he wanted .... and it blew me away. He repeatedly describes how he simply used the phone to compromise organizations, from personal information on individuals through the DMV to requesting wiretaps on the FBI. What really blew me away was his description of how he gained access to the source code of almost every commercial Unix operating system and mobile phone, bypassing the most advanced security of its time by simply tricking people.
The reason I'm so excited about this book is there is no other resource I can think of that demonstrates the power of social engineering and hacking the HumanOS. As Kevin repeatedly demonstrates, it does not matter what technology you have installed, it is the human that we need to secure.