So, I'm still on my approximately 25-book challenge.
The latest offering is The Runner's Handbook by Bob Glover. At 700-plus pages, it's a doozy. But, it's a good one. I've taken a few exercise physiology courses and used to be an athlete but I've only recently reaffirmed my commitment to exercise, and I'm completely new to running.
This book was full of clinical and academic studies, facts, figures, tables, tests, suggestions, training schedules, epidemiology, and more. Any running related topic you can think of is probably touched upon in this book. I feel like I've got a solid understanding of the current (or within the last decade anyways) science behind running and how to do it well, without injuring myself, for the long haul.
One thing I didn't think about when choosing a few running books to read was history. But I sincerely enjoyed the stories of how various races evolved. Even more surprising to me was the history of women in distance running (did you know that women weren't even *allowed* to compete in many marathons until the 1980's?). The personal anecdotes of running successes, trials and tribulations, cancer-in-remission runners, and even running-related deaths and crimes made this book a much more well-rounded introduction to the sport than I expected it to be. I feel more steeped in the culture than I was just a scant 700 pages ago.
If you haven't put in years on the road and/or haven't been reading Runner's World for the last few years, I recommend this book to give you a solid broad background of the sport against which you can evaluate your own progress, fitness, and balance.