I reviewed Audrey and Bill: A Romantic Biography of Audrey Hepburn and William Holden, a crummy book about the two stars’ affair during the making of Sabrina in the early 50s, for The Washington Post. If decades-old Hollywood gossip is your bag, I recommend Karina Longworth’s podcast You Must Remember This. The author of Audrey and Bill, Edward Z. Epstein, is a former publicist; Longworth is film critic and historian. It’s a crucial difference.
UPDATE: Whoops, You Must Remember This already covered Hepburn and Sabrina.