I'm glad to see that someone (not me) has finally added a Wikipedia entry for TV producer Danny Arnold. Since there's already been a biography of Nat Hiken, Arnold is the TV behind-the-scenes person whom I think would be the most interesting subject for a biography, as a comedian and jack-of-all-trades showbiz guy who became a very important and influential showrunner.
A lot of his work was ahead of its time: the early episodes of Bewitched certainly were, as I've explained before on this site; his Thurber-based sitcom My World and Welcome To It was one of the great one-season wonders; his failure The Wackiest Ship in the Army (loosely based on the movie of the same name) appears to have been a pre-M*A*S*H attempt to combine service comedy with serious war drama. And then there's Barney Miller, which in many ways was one of the oddest and most iconoclastic shows ever to become a mainstream hit (and the first successful cop show where the cops were the most interesting characters). He also seems to have had a knack for improving shows he was involved with; in the years when he was running That Girl he made it into a much better show than it originally promised to be in its first season. The title "producer" of a TV show was a position that meant, or could mean, a lot of different things at that time, but Arnold made it mean something close to the modern position of showrunner, in that any show he produced would start to show aspects of his style (so his episodes of That Girl show some of the same obsessions he'd worked through in Bewitched, and I just watched a That Girl where he introduced a huge number of the cops-in-drag jokes he'd later bring to Barney Miller).
The other biography-worthy aspect of Danny Arnold was that he appears to have been somewhat rage-filled and maybe a bit nutty. Few people who worked with him seem to have been terribly fond of him as a person. Theodore Flicker, who is credited as the co-creator of Barney Miller, despised Arnold; director John Rich, who helped Barney Miller get picked up after the networks turned down its weak pilot presentation film, got into an argument with Arnold and left after two episodes. And when Rich took his name off the second episode, Arnold took the director's credit himself (is that even allowed under union rules?). His all-day, all-night rewrites on Barney Miller drove the cast to distraction and finally made it impossible to continue shooting the show in front of a live audience, because he never had the scripts ready in time. One of the few people he seems to have actively gotten along with was Marlo Thomas, and, as I've said in an earlier post, it appears that they liked each other because they were both impossible for anyone else to get along with.
Arnold's apparent breakthrough success, Barney Miller, was actually the end of the line for him; he never had another successful show. So a biography would have a clear, if slightly depressing, trajectory to it. There may not be all that much to know about the guy apart from what is mentioned here and on Wikipedia, but then again maybe there is.
Here is Arnold making a cameo on That Girl as a harried television producer.