I am no expert in Scientology, but here’s what I have gathered of their odd beginnings.
L. Ron Hubbard began writing science fiction stories for magazines in the 1930’s. He later published a book in 1950, titled “Dianetics: The Modern Science of Mental Health”. In this book, Hubbard introduced auditing, which is a sort of counseling session where the auditor asks questions to allow the person to achieve a sort of higher state of awareness. As Hubbard’s beliefs gained momentum, the first Church of Scientology opened in Los Angeles in 1954. After Hubbard died in 1986, a high ranking Scientologist, David Miscavige, took over. Famous Scientologists who have boosted the popularity of the religion include Tom Cruise, John Travolta, and Kirstie Alley. The church has battled the legitimacy of their “religion”, but ultimately the United States recognizes it as a legitimate religion.
A great unbiased source of everything Scientology is this site.
Another great resource on the history and beliefs of Scientology can be found here.
A little more critical history of Scientology is detailed here.