Bingley, I will try to answer completely, but there was much training I did which was provided by the government that is not available outside the government. Most of this training is centered on communications, for all purposes.

Richard Mullender teaches in the UK. He is the former chief trainer for the London Metropolitan Police (New Scotland Yard) National Hostage and Crisis Unit. He is a fantastic teacher. He focuses on listening, which is a skill few people seem to really have. He does run open courses. Mullenders.org

The Institute for Analytic Interviewing is a great one week course, but specializes in law enforcement interviewing. I will say that what they teach is useful to anyone who deals with people, in any situation or capacity. iainterviewing.com

Rory Miller teaches some very practical courses on conflict and violence, and the individual level. His Conflict Communications is great, and he can carry it all the way to practical fighting. He has some extensive experience doing this kind of work, and he studies the science and teaches well. Chirontraining.com

Dr. David Matsumoto has some on line training in recognizing facial expressions and emotions. This is very necessary if you are worried about detecting deception or early detection of threats. He worked with Dr. Paul Ekman and has built on Edman's work. humintell.com

Randy Markoz does not have a web site, and he is working for another company, but he runs a course that includes understanding personality (based on the Myers-Briggs personality inventory) and how that affects communications. I find this very useful in dealing with people as it informs you how they see, interpret and interact with the world. This goes a long way in helping you anticipate their actions and how to communicate more effectively with them. I would have to facilitate a link up with him.

Books:

Personality

Gifts Differing

Please Understand Me

Understanding personality is a big help in assessing people and their intentions. It can also help in assessing people for the best fit in a job or task. It also helps you understand the best way to communicate with them. You start by understanding your own personality, then you can begin to see it in others.

Emotions Revealed

Telling Lies

Understanding emotions is critical to understanding people, and detecting deception. Detecting deception is generally poorly understood by people. You are not detecting lies, you are detecting a difference between the words someone is using and their actual emotional responses. Matsumoto's training helps you identify the emotional responses.

Conflict Communication

Facing Violence

Meditations on Violence

Rory Miller's books are very well written and practical. They are not long, and not written for an academic audience. He also has videos on his training.

If anyone is looking for more resources related to this subject just let me know.