I love to find books that are truly great. My favorite kinds with kids are funny without being obvious. Not the kind that are like, "hey, didja get it? This is funny BECAUSE..." I like kids to have to be smart enough to get it. I ALSO love when kids learn about all the books one author has written. I like when they say, "oh that's a book by..."
One of my favorite authors that satisfies both truly great books AND has written lots is Robert Munsch. Kids like his name and his stories help me teach great writing and story telling.
I start with a book like Mortimer.
Mostly I just use these books as talking points and looking at writing from a writer's perspective.