If you'd like to read some retellings of the King Arthur or stories about characters from the myth, these books and movies may interest you.
Mists of Avalon by Marion Zimmer Bradley is a retelling of the Arthur myth through the eyes of the women around him.
Half Sick of Shadows by Laura Sebastian tells the story of Elaine who, in the Arthurian legends, was in love with Sir Lancelot and died of grief because he couldn't return her love. Elaine was the inspiration of the poem The Lady of Shalott by Alfred Lord Tennyson (published in 1832) and the painting by John William Waterhouse. In Half Sick of Shadows, Elaine can see into the future. After growing up in Avalon with Arthur, Morgana, Guinevere and Lancelot, they all return to Camelot where Arthur will rule.
Morgan is My Name by Sophie Keetch is the story of Arthur's sister Morgan (sometimes called Morgana or Morgan le Fay). As a young girl, Morgan is spirited and eager to learn but her step-father Uther Pendragon tries to keep her obedient and in her place. The story follows Morgan's struggle to claim her life despite the restrictions she faces as a young woman.
Once & Future by A.R. Capetta is a young adult science fiction reimaging of the Arthurian Legend. Ari Helix's spaceship crashes on Old Earth. When she pulls the sword from the stone, she's discovered to be the latest reincarnation of King Arthur.
The Skystone by Jack Whyte starts before King Arthur with the Roman Empire in Britain. The events in The Skystone set the history for Camelot and King Arthur's rule.
The Guinevere Deception by Kiersten White is a young adult novel that focuses on Guinevere who is sent to wed King Arthur and protect him.
Over the years, many movies have been done about King Arthur. Here are some that you can borrow from TSPL:
King Arthur: The Legend of the Sword tell the story of Arthur being robbed of his birthright and growing up in the back alleys of the city. But once he pulls the sword from the stone, he is forced to acknowledge his true legacy - whether he likes it or not.
Arthur: King of the Britons is a documentary done by the BBC looking at the possibly reality of King Arthur as a 6th century warlord.
Merlin - was a TV series done by BBC that chronicles Merlin and Arthur as young men. TSPL has all five seasons.
The Kid Who Would be King is a movie set in current time where a young boy discovers Excalibur and sets out with his friends to save the world and discover the truth about who he is and his father.
Excalibur is the story of Arthur finding the sword and rising to King to unite Britain.