I judge books by their first paragraphs. The most definitive example of this maxim working for me was when I was evaluating two books about the history of Seattle.
The first book’s first paragraph gave an introductory picture of Seattle by noting its many data points—latitude, longitude, average rainfall, population, etc., etc.
The second book’s first paragraph read:
The hills are so steep in downtown Seattle that some of the sidewalks have cleats. They used to be steeper[...] so steep that members of the Seattle Symphony, who had to climb three blocks[...] rigged a pulley to carry the instruments uphill, so that strangers in town were sometimes startled to have a cello or a tuba swoop past them on the street.
And that was all the info I needed to make a decision.