Sauron was originally a Maia to Aule. (A maia is a lesser god who is subservient to the greater ones)
He eventually went to the service of Morgoth, and became his lieutenant.
Sauron returned and entered Mordor and erected the tower of Barad-Dur. When the Numenoreans challenged him, he went as a prisoner, and eventually became a trusted advisor. The Numenoreans tried to fight the greater gods and they all died.
Once he came back, he slipped back to his old ways. He aided the Elves in making rings of power, and eventually he made the One Ring, or the Ruling Ring.
Later on, Sauron gave some of the rings of power to men, and eventually they fell under the power of the Ring and became the Nazgul.
The words on the ring are: One ring to bring them all and in the darkness bind them.
The elves and men formed the "last alliance" and went to fight the hosts of Mordor. They laid siege to Mordor. Then Sauron came and killed quite a few elves and men before killing Gil-Galad and Elendil before Isildur cut the Ring from his finger. Barad-Dur was leveled to the ground, but its foundation was not destroyed, because its power was tied with the ruling Ring.
Sauron hid in Mirkwood, and the wizards came from over the sea to challenge Sauron's power. (The wizards are also lesser gods) Sauron eventually went back to Mordor and rebuilt Barad-Dur.
Eventually, Frodo and Sam threw the Ring into Orodruin, or Mount Doom, and the Ring was destroyed and the power of Sauron was diminished forever.
"Damn yo, this guy has written so much about Sauron I'm ready to gouge my eyeballs out and kill myself"
The unexplained phenomena that occurs when somebody writes some successful (albeit awful) literature on vampires, EVERYBODY decides they want to get in on the act and before you know it bookshelves are crammed with novels about romantic relationships with vampires, and you can't escape the fact that so much hype is made over the "New Moon" trailor that you would think it was the coming of Jesus.
Person 1: Hey did you read that erotica novel where a women has sex with 15 vampires and their marble like, cold cocks? (Come to think of it, if a vampire is dead, they would have no blood circulation-Edward is always described as being cold- how could they "get it up"?)
Person 2: OMG NO WAI11!!!@~~
Person 3: Ya, everybody is jumping on the vampire bandwagon...