Satanism is an umbrella term,like Paganism or Witchcraft etc.
Not all Satanists are Religious,just like not all Witches are Wiccan.
Laveyan Satanism is probably the best known of the Atheistic forms.
http://www.churchofsatan.com/home.html
Then there is Spiritual or Theistic Satanism.
Again,there are several paths in this paradigm,also
Temple of Set,is a well known and established order.
http://www.xeper.org/pub/pub_resources.html
We have a venerable member here,Venus Satanas, who runs her own site 'Spiritual Satanist':
http://www.spiritualsatanist.com/
And Diane Vera's site:
http://theisticsatanism.com/
Then there is Demonolatry,another variation of Satanism:
http://www.satanservice.org/satanism-bibliography/
There is a lot more to Satanism than meets the eye,I haven't even begun to list Luciferianism or Gnostic Luciferianism or Luciferian witchcraft etc.Or any of the other groups and organisations.
Of course there are also Solitary and Eclectic Satanists,who suscribe to some or none of the above and who forge their own paths.
You haven't even scratched the surface yet,sasquatchjc,lol.I recommend doing some online research and perhaps hitting up the search /archives here,you may find some surprising information. [thumbup]