ive read it.. read the necronomicon, the satanic witch and the book of nod.. lots of stuff like that....  they don't believe in the devil... satanist believe you are your own god... they believe in doing what you want rather then be restrained by rules... they don't bleive in heaven or hell...  they are some of them that do pointless rituals but most don't.... they call themselves satanist as a rebellion against the mostly christian run society....  nothing ive ever found or read makes them sound evil but just as i said rebelious, for the outcast of society.. the one i read was wrote by anton szandor levay.. its not a book to be afraid of lol

for the record im atheist.. i don't believe anthing.. ive read the holy bible and the lots of catholic and other christian and even some shinto related books.. i just study stuff