The problem with "Proficient Motorcycling" is that it will only convince those mature enough to understand the precautions, dangers and survival techniques involved in motorcycling. Most of the advice in these 300-or-so pages is pretty much obvious stuff to anyone who isn't particularly suicidal : do not drink and drive, slow down at night or when you can't see what's ahead, wear protective gear in the rain, take frequent rests, adapt your speed to your skill level. Nothing that a gung-ho 20 year-old with a Suzuki GSXR will ever listen to, and nothing that a beginner but responsible motorcyclist won't figure out by him or herself.
There are some excellent chapters on the limits of traction and how to properly balance the different factors that define it (throttle, brakes, lean angle, road surface). Personally, I appreciate the conservative approach to riding and the everyday situations shown in the photographs accompanying the text. The author doesn't try to explain how to negotiate curves at maximum possible speed with the kneepads scraping the pavement, but rather on how to have the most fun while maximizing your chances for survival. The chapter on how to deal with aggressive drivers around you is a very good text but, again, if you haven't figured out by yourself that avoidance is more beneficial than confrontation then you aren't going to learn anything new.
My point is : this is a very well-written guide that will be of little use to anyone who isn't already receptive to its teachings, in which case most of the book is stating the obvious.
Be warned that "Proficient Motorcycling" is concerned mostly with riding in the United States, with an emphasis on deer and moose collisions which might seem a bit extreme. Also, all speeds are stated in miles per hour (with distances in feet) which takes some mental conversion time when reading. Nothing too taxing, though.