The first book in the Harry Potter series is "Harry Potter and the Philosopher's Stone," published in the UK in 1997 (and titled "Harry Potter and the Sorcerer's Stone" in the US). Written by British author J.K. Rowling, the novel introduces readers to the young wizard Harry Potter, his friends Hermione Granger and Ron Weasley, and their adventures at Hogwarts School of Witchcraft and Wizardry. The book was a significant success, launching a beloved series that captivated readers worldwide and contributed to a renewed interest in children's literature.