>>213746392
I don't know about general documentaries but there are several on specific topics I'd recommend.

Hollywood Singing and Dancing: documentaries for each decade 1930s-current, and one that covers that whole period for those who only want an overview. Excellent interviews with actors and actresses and other creative types.

Garbo: feature length doc narrated by Julie Christie. Available from TCM.

Astaire and Rogers: Partners in Rhythm - essential viewing for Fred and Ginger fans, includes very rare video interview footage with each.

Rita: 1 hour doc on Hayworth, including lots of great bts footage. Also includes her 1937 western (!) with Tex Ritter.

Grace Kelly et al: from The Hollywood Collection, lots of profiles of Golden Age actresses.

Also check out Bogdonavitch's profiles of classic Hollywood directors. I'd also recommend Kubrick : A Life in Pictures.