S.E. (Susan) Hinton is a famous American author, best known for her novel The Outsiders. Published in 1967, the book about teenage social status, cliques and coming of age is considered a classic of American literature. It was made into a movie in 1983 directed by Francis Ford Coppola.
Hinton is a fan of Supernatural, as reported here when a Buddy TV reporter visited the set on September 9, 2008:
Another pleasant surprise was that S.E. Hinton, the author of The Outsiders and Rumble Fish, was hanging out with the boys as well. She is a huge Supernatural fan and asked Eric Kripke one day if she could pay a visit to the set, so he invited her out to Vancouver for a couple of days. She told me that she got into the show because she has an interest in paranormal stories, but then just fell in love with it because of the excellent stories and the mix of humor, drama and thrills and chills. Imagine having a fan girl moment with a world-famous novelist!
Hinton's first visit to the set was during 4.06 Yellow Fever
Susie also writes fanfic. On December 9, 2011 she tweeted :"Took one of my SPN fanfics to read in writing group today. It was a big hit, tho no one else watches the show. My fanfics are nothing special, mostly just slice o life stuff with no plot, but it's fun. Eric likes them.".
- The Symbolism in Sam's Hair by S.E. Hinton Posted on Twitter Jan 15, 2011
April 2012: Susie visited the set for the fifth time during the filming of 7.22 There Will Be Blood. As she promised her Twitter followers, she passed on a hug from the fans to Jared and Jensen Source.
- Susie's set report via her Twitter collected in Storify
August 2012: Susie visited the set during the filming of 8.05 Blood Brother.
- A Day on Set - what happens during a filming day - Susie's tweets collected in Storify
April 2013: Susan again visited the set during the filming of 8.23 Sacrifice.
- Set visit - Susies's tweets from her visit collected in Storify
- Interview with Hinton about her love of Supernatural by flavorwire
September 2013: tweets from Susie's visit to the set during the filming of the 5th and 6th episodes of season 9
Hinton references in Supernatural
- As an homage, in 4.13 After School Special in Sam's English class, Mr. Wyatt has notes about The Outsiders on the blackboard.
- In 4.15 Death Takes a Holiday, Pamela says "And guess what? I'm sick of being hauled back into your angel-demon, Soc-Greaser crap."
Socs and Greasers are rival groups, divided by socioeconomic status, The Outsiders.
- Hinton confirmed that there was a copy of The Outsiders at Bobby's place - amongst many Jackie Collins novels! 
- in 8.23 Sacrifice, Metatron is seen reading a copy of Hinton's book Rumblefish.