Another interesting writer's handbook that I've been reading is called "On Writing Well" by William Zinsser - a guide specifically for writing non-fiction.

In one chapter, he talks about "clutter" or what I'm calling "wordy words". For example, listen to any politician speak. Any idea what they are saying? Or when you attend a company business meeting where a major layoff is about to take place (I experienced a few of these in the 1990's.) The CEO or "company henchman" tries to explain to the employees, in as many words as possible, why downsizing is for the good of the company and all of the employees. But they just never quite get around to saying it so you leave the meeting wondering what just happened...or what is about to happen.

As the saying goes, keep it simple stupid (KISS). Just say what you need to say, particularly in the non-fiction genre. Too many unnecessary words can ruin what may otherwise be a useful and noteworthy book.