Together with the Reid technique, W-Z provides some of the best training in interrogation available today. The book covers most of what one needs to know, but is probably best used as a reference - practical training in this field is rather more important.
The only problem I have with W-Z is that there is clearly pseudo-science lurking at the edges of what they teach. Neuro-liguistic programming is bunk, but they reference it in the book - and they did as well during the advanced cold-interviewing seminar I attended two weeks ago.
I know this is not your normal recreational reading, but it was handy, and actually, quite fascinating. I find that I listen to conversations quite differently now. Probably handy for anybody who has teenagers! LOL