The Church of Satan and Anton LaVey
The CoS was started by Anton Szander LaVey on April 30, 1966. On that night, Lavey shaved his head and declared himself the Black Pope and the High Priest of the CoS. Since then, he has written many books on satanism, all of which you can obtain through practically any bookstore. I would recommend that anyone interested in satanism should read some of his books.
Sadly, LaVey died on October 29, 1997. Blanche Barton is now the High Priestess of the CoS, as appointed by LaVey himself. There has been some disagreement about the position of LaVey's daughter, Karla LaVey. I know little about the whole situation, except this: H.P. Barton once named Karla LaVey co-High Priestess. Since then, they've had their differences and disagreed about certain aspects of the CoS. H.P. Barton has accused Karla of misrepresenting the CoS: saying things that were either not true, or things that H.P. Barton didn't agree with, or giving interviews when the CoS did not wish her to. I'm not sure who has been right here, but I do tend to side with H.P. Barton since she has won the respect of so many other members within the CoS and is now currently the High Priestess.
On another topic, I would like you all who are interested to go here and read about the ongoing battle to save the Black House, which was once the home to LaVey and the CoS.