There have been a number of books whose plot involves children getting sucked into a video game. The following novels all rely on this story line: "Demons Don’t Dream" by Piers Anthony, "The Glitch" by Ronald Kidd and "Only You Can Save Mankind" by Terry Pratchett.
Additional books in which kids are pulled into a video game world are "Finders Keepers" by Emily Rodda, "Keeper of the Kingdom" by H. J. Ralles, "Killobyte" by Piers Anthony and "Guardians of the Flame" by Joel Rosenberg. The "Otherworld Chronicles" by Nils Johnson-Shelton also follows that plotline. Because of the theme's popularity, many of these stories have been adapted for TV or the big screen.