Yeah, it is a huge subject and it’s hard to even figure out a place to begin. There really aren’t good one volume books that take in the whole era. You have to specialize to narrow it down to manageable proportions.
This recommendation might horrify purists, but if you want to start with light, breezy, story-packed books just to get the mythologized flavor of the place, search out the copious oeuvre of Bob Thomas.
He’s written a book about everybody who was anyone in the Golden Age. He did books on all the moguls - Selznick, Thalberg, Cohn, Warner, Disney. He’s done biographies of Joan Crawford, Abbott & Costello, Fred Astaire, William Holden, and Marlon Brando. He ghostwrote books for Debbie Reynolds and Bob Hope. And many of them were reprinted in recent years in trade paperback by New Millennium Press, so they should be easily available.
They won’t be scholarly reassessments of the age, but it doesn’t sound like that’s what you’re looking for.
If you want to go back even farther, the best book on the comedians of the silent era is Walter Kerr’s The Silent Clowns. That’s another older book that’s been reprinted as a modern trade paperback.
If it fiction you want, then check out George Baxt’s series of mysteries starring various celebrities as the detectives: The Clark Gable and Carole Lombard Murder Case; The Mae West Murder Case; The Fred Astaire and Ginger Rogers Murder Case; The Greta Garbo Murder Case; The Bette Davis Murder Case; and several others. They are bitchy in the best sense of the word, crammed with all the gossip of the day - which usually was no more true than gossip is today, and use the star’s on-screen personas rather than their real selves as characterization, except where it’s convenient to do it the other way round.
Try to keep it fun. It’s easy to take old Hollywood too seriously and frankly it’s a crime when people do. They were high school dropouts grinding out sausage for the most part, not intellectuals forging a new mythology for a technologized America. If they did any of that inadvertently, we’re the better for it, but stick with the real tinsel behind the fake tinsel and you’ll see the place for what it was.