These suggestions plus the thread Thudlow linked ought to get you off to a flying start, but I’ll add a few more:
Top of my list is A House With a Clock in Its Walls, by John Bellairs. If he likes this one, there are maybe ten or fifteen more books with the Lewis Barnavelt character, and he’ll love those too. From the Amazon review:
Lewis always dreamed of living in an old house full of secret passageways, hidden rooms, and big marble fireplaces. And suddenly, after the death of his parents, he finds himself in just such a mansion–his Uncle Jonathan’s. When he discovers that his big friendly uncle is also a wizard, Lewis has a hard time keeping himself from jumping up and down in his seat. Unfortunately, what Lewis doesn’t bank on is the fact that the previous owner of the mansion was also a wizard–but an evil one who has placed a tick-tocking clock somewhere in the bowels of the house, marking off the minutes until the end of the world. And when Lewis accidentally awakens the dead on Halloween night, the clock only ticks louder and faster. Doomsday draws near–unless Lewis can stop the clock!
Next, I’d recommend almost anything by William Sleator, a YA sci-fi author. My favorites are House of Stairs and Singularity. Again with the reviews:
House of Stairs- One by one, five sixteen-year-old orphans are brought to a strange building. It is not a prison, not a hospital; it has no walls, no ceiling, no floor. Nothing but endless flights of stairs leading nowhere —except back to a strange red machine. The five must learn to love the machine and let it rule their lives. But will they let it kill their souls? This chilling, suspenseful indictment of mind control is a classic of science fiction and will haunt readers long after the last page is turned.
Singularity-Sixteen-year-old twins Harry and Barry stumble across a gateway to another universe, where a distortion in time and space causes a dramatic change in their competitive relationship.
My son and I are currently enjoying Maniac Magee, by Jerry Spinelli. It’s a great bedtime book because it has very short chapters.
Amazon review: Maniac Magee is a folk story about a boy, a very excitable boy. One that can outrun dogs, hit a home run off the best pitcher in the neighborhood, tie a knot no one can undo. “Kid’s gotta be a maniac,” is what the folks in Two Mills say. It’s also the story of how this boy, Jeffrey Lionel “Maniac” Magee, confronts racism in a small town, tries to find a home where there is none and attempts to soothe tensions between rival factions on the tough side of town. Presented as a folk tale, it’s the stuff of storytelling. “The history of a kid,” says Jerry Spinelli, “is one part fact, two parts legend, and three parts snowball.” And for this kid, four parts of fun. Maniac Magee won the 1991 Newbery Medal.
