Biographical
This is the homepage of Stephen King's official site. There, you'll find links to a biography, a rumors page, and a feedback area, among many other things.
http://www.stephenking.com/
Here's a biography from an unofficial site. What makes it unofficial? How does the information here differ from that found at the site above? Is the information here necessarily less trustworthy than that found above?
http://www.horrorking.com/biography.html
Cultural
Over the years, King has sold hundreds of millions of books, but has met with mixed critical reception. His first book, Carrie, did get this positive notice, though. (Free registration required.)
http://www.nytimes.com/books/97/03/09/lifetimes/kin-r-carrie.html
You're probably aware that King has been a frequent contributor to films. Check out his filmography to get an idea the full extent of his contributions. Did the number of films in the list surprise you?
http://us.imdb.com/Name?King,+Stephen
Bibliographical
Have you ever read an author reviewing his own book? It doesn't happen very often, so why don't you take a look at King's review of his novel 'Salem's Lot? (Free registration required.)
http://www.nytimes.com/books/97/03/09/lifetimes/kin-v-guest.html
In a more conventional approach, King reviews Thomas Harris's novel Hannibal, and gives it a rave. Have you read it? Have you seen the movie? Both maybe? This page also has a link to Harris reading from the book. (Free registration required.)
http://www.nytimes.com/books/99/06/13/reviews/990613.13kingct.html