The Curriculum Center in the Lower level of JFK Library has thousands of children's books.
Many publishers provide book discussion guides on their websites too.
It is worth checking the Education databases for articles as well, along with bibliography books in the Zs in the Curriculum Center's teacher materials.
Bookmark these blogs, set them as home pages, add their RSS feed to a reader like Feedly, like them on Facebook -- keep up with what's out there in children's and YA books!