Here are several highly regarded reading lists you can consult. We have many of these books in our library
The State of California Recommended Reading Listprovides grade-specific lists for California students from kindergarten to 12th grade--
The Caldecott Medal winners--www.ala.org/alsc/caldecott.html
The Newbery Medal winners--www.ala.org/alsc/newbery.html
American Library Association Young Readers Book Lists---
Scholastic Books-www.scholastic.com/kids--books (mainly from Scholastic, of course) for children 6 to 13. Activities, contests and games related to such page-turners as Goosebumps.