Just a few recommendations of some I enjoyed:
The Salad Days by Douglas Fairbanks, Jr. - great, thorough autobiography that is a great look at early Hollywood up to about 1940
Wisecracker: The Life and Times of William Haines by William J. Mann - I really enjoyed this one because it goes beyond just the life of Haines and provides context for his story by going into depth about the gay culture in Hollywood
Bogart: In Search of My Father by Stephen Bogart - it's been awhile since I read it but it is a good one