If you liked The Giving Tree, check out these books by Shel Silverstein. If you haven't had the opportunity to get to know his work, I encourage you to do so. Every kid I know has been delighted with his funny and lighthearted poetry.
A Light in the Attic
Where the Sidewalk Ends: Poems and Drawings
A Giraffe and a Half
The Missing Piece (An Ursula Nordstrom Book)
The Missing Piece Meets the Big O
Runny Babbit: A Billy Sook
Have a very happy thanksgiving!