HARRY POTTER AND THE SORCERER'S STONE By J.K. Rowling Scholastic 320 pp., $16.95 Ages 9-12 There's something strange about Harry Potter. Sweaters shrink when he's near. Boa constrictors are mysteriously freed when he visits the zoo. Even his hair grows in a weird way. His Aunt and Uncle Dursley, who are about as awful as their name, and their son, Dudley (who's even worse), would cringe with embarrassment if anyone knew Harry was related to them. So they keep him hidden away in a closet - a rather dark and spidery one under the stairs. But all that changes on his 11th birthday, when Harry gets accepted to boarding school. "Harry Potter and the Sorcerer's Stone" is a gleeful, impish descendant of classic fantasies like "Charlie and the Chocolate Factory" and "The Wizard of Oz" and will no doubt join them on the shelf of childhood favorites. Chock full of fun and whimsy and stocked with some of the most engaging characters in children's literature, J.K. Rowling's first novel swooped up a handful of awards in Britain and went straight to No. 1 - on the adult bestseller list. Like Charlie in Roald Dahl's classic, Harry is handed a ticket out of his misery. But this one comes courtesy of a giant on a flying motorcycle. And the school Harry's been accepted to isn't exactly Eton. Harry, it seems, is a wizard - or will be once he's trained - and a pretty powerful one at that. As a baby, he somehow survived an attack by the evil wizard Voldemort that killed both his parents. So, to the excruciating embarrassment of the Dursleys, Harry is packed off to Hogwarts School of Witchcraft and Wizardry, where the fun really begins. Rowling takes childhood rites like shopping for school supplies and dealing with the class bully and gives them a magical tweak. For example, the big game at Hogwarts isn't soccer, it's Quidditch - a high-flying combination of dodge-ball, capture the flag, and basketball played on broomsticks. As soon as he moves into his dorm room, though, Harry realizes there's a mystery afoot involving a sorcerer's stone. It's up to him, along with his friends Ron and Hermione, to uncover the evil stalking their school - without falling behind with their homework. Will Harry lead his Quidditch team to victory? And will the evil Voldemort return to stir up trouble? (Does the Wicked Witch of the West hate water?) Rowling crams the book full of inventive details - like jelly beans that come in every flavor, including sardine - and her rollicking style keeps the reader careening along with the plot. The only flaw is a too-abrupt ending that doesn't completely satisfy. But that may be partly due to a reader's unwillingness to put down the tale. A sequel is due in September. If it's half as charming as the original, all is forgiven. Yvonne Zipp is on the Monitor staff.