Give "The Case for Christ" a read. It was my first step in truly accepting Christ into my life.

I've struggled with my faith for a long time so to read about the evidence for his existence really helped me. The book's chapters also include additional readings from other authors, theologians and professors that one may pursue as additional knowledge on the subject.

That all being said, may God bless your son and your family. I'm thrilled to hear things are going well for him.