Danny Torrance
Danny is really the catalyst for the entire story. He is the son of Wendy and Jack Torrance, a couple who have relocated to the Rockies in Colorado so that they can have a fresh start and hopefully save their marriage. Danny has supernatural powers that his parents are unaware of but that are recognized by Dean Halloran the hotel chef. He is able to mentor Danny and it is largely thanks to him that Danny begins to understand the shining and how to use his powers to combat the evil malevolent spirits in the hotel.
Danny loves his parents but comes to understand that he needs to save his mother from his father as his father has been possessed and is no longer really himself; he is a front for the hotel, a mask that it is wearing. He is a courageous kid. He stands up to the hotel, and also realizes that his best chance of saving himself and Wendy is allowing the hotel to blow up because of the swelling boiler that Jack has forgotten to fix. Danny emerges alive at the end of the book, affected by what he has just seen, and mourning the loss of his father.
Jack Torrance
Jack is a man struggling with anger issues that threaten to end his marriage. He loves his wife and family, but a combination of poor anger management and alcoholism have made him abusive on occasion. He has been fired from his job as a teacher after putting his hands on a student, and he is hoping that the move to the hotel will be a fresh start, earning him some money, offering a change of scenery and enabling him to work on his writing.
Jack is the target for the hotel and is fairly easily possessed. Although he does manage to fight this in the most extreme circumstances, such as when he sees his son's life in grave danger, he is ultimately powerless to fight back against the malevolent force possessing him. He is killed when the hotel explodes at the end of the novel.
Wendy Torrance
To call Wendy long suffering would be an understatement. She has endured a lot in her marriage; she has taken a great deal of abuse from Jack but wants to make the marriage work and give Danny the chance to grow up in a loving home with both parents. Initially she is troubled by Danny's discomfort in the hotel and wants to leave but is persuaded to stay by her son because he knows how important the job is to Jack. Wendy's role in the plot is mostly peripheral, as a mom to Danny or a wife to Jack. She is a fighter, and fights off the possessed Jack several times. She survives the explosion and moves her son away afterwards.
Delbert Grady
Delbert is not a living character in the novel, but a dead one, sort of a dry run for Jack in the hotel's viewpoint. He is the winter manager before Jack and succumbs quickly to cabin fever, and goes mad. He reappears in the hotel bar and acts threateningly towards Jack, also trying to persuade him to do as he did and kill his family and himself.
Dean Hallorann
Like Danny, Dean has supernatural powers, and he immediately recognizes them in the young boy. He acts as a mentor to him, and teaches him how to understand his powers and how to use them. He is also the savior of the family, as he rushes back from Florida to help them reach safety.
The Overlook Hotel
How can a hotel be a character? It's an inanimate building, not a person. Except that it's not inanimate, and although not a person, the Hotel is a malevolent force that possess specific people in an effort to cause as much damage and carnage as possible. In this way it is personified and is a character in the book. The Hotel is neutralized at the end of the book when its physical facade explodes.
