"The Grapes of Wrath" by John Steinbeck
"Of Mice and Men" by John Steinbeck
"20,000 Leagues Under the Sea" Jules Verne
"To Kill a Mockingbird" Harper Lee
"The Catcher in the Rye" J.D. Salinger
"Where the Red Fern Grows" Wilson Rawls
The Narnia Series by C.S. Lewis
"The Hobbit" & "Lord of the Rings" by J.R.R. Tolkein
"Gulliver's Travel's" by Jonathon Swift
Ray Bradbury and George Orwell are great authors, but it depends on how old your son is.
And just for good measure "The Theory of Relativity" By Albert Einstein
Thanks for wanting to give your son the gift of literature.