Strange Sects and Curious Cults, first published in 1961, is a well-written overview of a number of important religious sects and cults. Author Marcus Bach divides these into three categories: the sex sects, conscience cults, and the utopianists.
The first group includes ancient Baalism of Mesopotamia, Osirism of Egypt, Shivism of India, and more recently, Voodoo of Africa and the New World. The Conscience Cults include the Penitentes, Apocalypticists, Father Divine of Harlem, the Oxford Groupers, and Psychiana. The section on Utopians includes the now-vanished Russian Doukhobors, followed by the Shakers, Amanas, Hutterites, and Mormons.
For anyone looking for a good introduction to offbeat religious groups, Strange Sects and Curious Cults will provide a useful background and serve as a basis for further research.