Astrophysics for People in a Hurry by Neil deGrasse Tyson is a short, accessible book on the universe for readers who do not have time for a textbook. Tyson covers the Big Bang, dark matter, dark energy, exoplanets, and the basics of how astrophysicists think, in chapters short enough to read in a coffee break.
It is one of the best selling popular science books of recent years for good reason.