May God's Peace, Love, Mercy, Blessings & Graces be with you and to all!
Congratulations to your son's upcoming confirmation. What a blessing! It is good that your son is very much interested in learning more about our awesome Catholic faith. Our Good Lord surely is showering him with lots of graces.
You could never go wrong with the books written by Patrick Madrid - Where is that in the Bible, Why is that Tradition, Answer Me This, Pope Fiction, Surprised by the Truth are all very good books to have. You can visit the website below for a full listing of his books.
Another great author & theologian is Scott Hahn. Your son will definitely learn a lot & will come to love & appreciate his Catholic faith more. He will definitely be fired up with his Catholic faith after reading Scott Hahn's books. Among his writings are The Lamb's Supper, Lord have Mercy, the healing power of Confession, Faith Charts, Bible at a Glance, Rome Sweet Home. For a full listing of his work, visit the website below.
Regarding the Bible, please get a Catholic Bible such as New American Bible because the Protestant bible such as the King James version is missing 7 books. You want to have the fullness of Truth not just part of it so get a Catholic Bible.
Hope this helps. Take care & God bless!
Praying for you and for all!