Whether a Satanist worships Satan or not, they are devoted to the principle of self-divinity. They believe that all sentient beings has a spark of divinity. THey attempt to nurture their own and respect other's. Here are some general rules they abide by.
As InHarmony said, Satanism is about recognizing your own immediate divinity. You are God, the highest power in your life. It's really not a "scary" religion, in principal, but people can't get over the word Satan.
Perhaps Satanism is actually the worship of the Egyptian God Set? Because, to the Herbrews, he is known as Satan.
Just a bonus trivia,the inversed Pentagram originally belonged to the Egyptian Satan, and not the Catholic one, and it has only recently been used to symbolize an evil force.
Satanism/Luciferianism is more like a spiritual pratice of the adversary either be Satan,Lucifer,Set,Tiamat,Kingu,Leviathian/Yam Nahar,and Ahriman/Angra Mainyu. They don't nescessary worship anything but take the aspects of the adversary into one self knowing that they are the only god there is.
Satanism is all about spiritual advancement, bettering the world and yourself with the end goal of completing the Magnum Opus which is spiritual and physical perfection. Satanic Gods are the Origional pagan Gods eg: Astaroth is the Egyptian Goddess ISIS, to the Sumerians INANNA. Satan is Odin,Enki,Ptah. The Gods are very real and are help to us who are dedicated (satanist)and respectful.Do NOT contact Our Gods out of curiosity or for fun. Also Set is not Satan, but one of Satans 7 Sons. He is known as the Demon Sytry/Sitri. For more information reguarding spiritual Satanism visit the Joy of Satan website. As there is far too much to explain and answer.