Here are some other books on the subject. They help understand how people make decisions, how the press influences you, how to try to get people to do what you want them to do and how to resist this type of influence. Understanding the techniques is like an inoculation against other people's influence. Obviously these techniques can be used for other than good intentions, but they are critical for accomplishing things as well.

http://www.amazon.com/Age-Propaganda-Eve...8701&sr=8-1

http://www.amazon.com/Mind-Wide-Open-Neu...8728&sr=8-1

http://www.amazon.com/Blink-Power-Thinki...8749&sr=8-1

http://www.amazon.com/Sources-Power-Peop...8775&sr=8-1

http://www.amazon.com/Memory-Enhancing-T...8829&sr=8-1

http://www.amazon.com/True-Believer-Thou...8876&sr=8-1

http://www.amazon.com/Resistance-Persuas...8918&sr=8-1

http://www.amazon.com/Covert-Persuasion-...9069&sr=8-1

http://www.amazon.com/Influence-Psycholo...9187&sr=8-1

As far as the training is concerned, it focuses on keeping the subject communicating to you, and that means reducing hostility, building trust (yes even when interrogating a terrorist) and making the subject feel that he can depend on you. It also emphasizes detecting deception. Understand that there is no such thing as a lie detector. Not a mechanical device nor a human one. You can detect when someone is concealing something and with proper interviewing (communicating) you can drill down to what it is. You can also help someone remember things which they would not otherwise come out with in the interviewing process. Little details which might remain hidden or things which they could not otherwise determine the relevance of.

Some of the courses last for weeks and some are just a couple of days.