There are many films explicitly about Manson, and even more loosely inspired by him and the deeds attributed to him & 'The Family.' Most of them are worthless except as pure exploitation. This is the only one that provides more than a snippet of actual interview footage with the man himself. It is primarily for this reason that I strongly recommend it. If you have any curiosity, or interest in Manson, whether you despise or admire this legendary American outlaw, you'll want to see "Charles Manson, Superstar" to augment your perception of him. Be advised that the makers of this film are evidently Neo-Nazis, and their biased approach is about as subtle as a brick dropping on your head. Even if Manson was/is a Nazi, I think such indulgences as the interview with James Mason, American Neo-Nazi, detract from rather than add to the film. On the plus side, George Stimson was a consultant on this film, and he was a confidante to CM, and onetime webmaster of the "official" Manson website.
Of all the films about Manson, this one, however amateurish, patronizing and biased, is the most legitimate, if only in the sense that it allows Charles Manson to speak for himself.
Other films of note on the subject are "Manson" [1972] and "The Helter Skelter Murders" aka "The Other Side Of Madness" [1970].