It somewhat of an old book, (as scientific non-fiction goes) published in 2000, but one of my favorite science books of all time was Genome, by Matt Ridley. It was shortly after the human genome project was completed. Ridley took each chromosome in the human body and examined something interesting on each chromosome. Each chromosome got a chapter. Sometimes it was a bit of a stretch (Ridley is a science writer not by any means a scientist. For example, there was a "Free Will" chapter, because the chromosome basically didn't have anything interesting on it) but a lot, if not all of it, of it was very good information, particularly if you don't have a solid background in biology and human genetics.