The Soc/society for Satanists be it Theist or Atheistic!
Ave Satana!
Hail Satan!
Satanism has many groups under its umbrella the group you are most likely to encounter are the leveyan satanists they are Atheistic they believe Satan is an idea not an entity, they have a book called the Satanist bible wrote by the Church of Satan's found Anton Levay
Groups of Satanism
Starting with the Atheisic groups
Levayan Satanists(sometimes part of the Church of Satan)
Atheist Satanists
Theistic groups are a bit more varied in their beliefs.
Demonolotry practioners
Lucifarians
Setians/Temple of Set(No longer considered an Satanist group by their own choice and stance only including it as they were considered Satanists when i learnt about Theistic Satanism)
Satanists who worship the Christian Satan(rare but exist) i think this is called duotheism and is kinda like a reverse christianity.
The Church of Azazel
The Obolisk( they are luciferian)
Church Lucifer
First Church of Satan(No affiliation with the Church of Satan)
Joy of Satan(i will deal with these scum bags in its own post)
Reformed Church of Satan
Church of the infernal
Cathedral of Satan
Coven of bel's fire
there are tons of groups there in the Theistic Satanism camp its just a matter of finding out if they are seperate to the bigger groups or a coven in that group.
Independant Satanists also exist these Satanists are in the larger view technically part of one of the groups due to their beliefs matching however they do not consider themselves a part of a specific group, most demonolotry practioners are part of this they identify as demonolotory practioners but not not part of a group or a coven or kabal or whatever you wish to call it
I will edit this post to include Satanist sects in the future as well as info about the black mass and Satanist groups which people can go to.
good blog for Satanists of the Theistic kind
http://theisticsatanism.com/