The Yezidis don't quite fit the mainstream view of Satanism, but they're a very interesting group, nonetheless. razz
The Yezidis, if you've heard of them, have a reputation of being "Satanic." Considering that their god IS the adversary of Christianity, Judaism and Islam, there is very good reason to make this claim. However, the Yezidis consider their god as Good rather than Evil, and follow very strict religious laws.
The Yezidi people are ethnically Kurdish, and the majority of them live in northern Iraq. There are about 500,000 of them in the world, and this number is shrinking, as their religion does not accept converts.

The Yezidis believe they are descendants of Adam alone, as opposed to Adam and Eve. Adam and Eve had a contest to see whether man or woman would give birth and Adam won. Adam had a child, but from that point on, woman was the one who gave birth. Yezidis keep to themselves, believing that those not of Adam alone are unclean.
The Yezidis believe in the four elements, earth, air, fire and water, and that everything can be attributed to one of these elements. They try to keep items of opposing elements apart as much as possible in order to maintain the power of each element. Wearing blue is forbidden in their culture, as is eating lettuce and urinating while standing. All of these rules are in some way connected with the elements.
The major religious holiday of the Yezidis is an annual pilgrimage to the tomb of one of their ancient kings, where an ox is sacrificed on the altar.
More info: http://en.wikipedia.org/wiki/Yazidi
Yezidi holy scripture: http://www.sacred-texts.com/asia/sby/index.htm