2) Here's a great piece that puts Manson into the cultural context of California in the late 60's:
"For the uninitiated, the story goes something like this: Toward the end of spring, Wilson picked up two young hitchhikers, Patricia Krenwinkel and and Ella Jo Bailey, both of whom turned out to be members of Manson’s cult. He dropped them off, but soon encountered them again. The trio headed back to his mansion in the Pacific Palisades. Wilson left to record with the rest of The Beach Boys, and when he returned, he was greeted by a crazed-looking stranger in his driveway. The man was none other than Manson himself, and to assuage Wilson’s apprehension, he reportedly knelt down and kissed his feet.
The next few months saw Manson and his cadre of women moving in with Wilson, who allowed them to leech from his superstar status in exchange for group sex and servitude. The two even began collaborating together musically, so much so that Wilson introduced Manson to The Byrds’ producer Terry Melcher."Manson and his cult decided to murder Melcher. Melcher wasn't home. Roman Polanski was renting the place out and he wasn't home either, but his very pregnant wife and some of her friends were.
3) And perhaps most intriguing, how science fiction authors Robert Heinlein and L. Ron Hubbard gave us Manson in the first place:
"In 1963, while a prisoner at the federal penitentiary at McNeil Island in Washington state, Charles Manson heard other prisoners enthuse about two books: Robert Heinlein’s science fiction novel Stranger in a Strange Land (1961) and L. Ron Hubbard’s self-help guide Dianetics: The Modern Science of Mental Health (1950). Heinlein’s novel told the story of a Mars-born messiah who preaches a doctrine of free love, leading to the creation of a religion whose followers are bound together by ritualistic water-sharing and intensive empathy (called 'grokking'). Hubbard’s purportedly non-fiction book described a therapeutic technique for clearing away self-destructive mental habits. It would later serve as the basis of Hubbard’s religion, Scientology.
Manson was barely literate, so he probably didn’t delve too deeply into either of these texts. But he was gifted at absorbing information in conversation, and by talking to other prisoners he gleaned enough from both books to synthesize a new theology. His encounter with the writings of Heinlein and Hubbard was a pivotal event in his life. Until then, he had been a petty criminal and drifter who spent his life in and out of jail. But when Manson was released from McNeil Island in 1967, he was a new figure: a charismatic street preacher who gathered a flock of followers among the hippies of Haight-Ashbury in San Francisco."