Thanks everyone. I purchased most of the K materials and the preK dough letters. This is the first school program type thing I have tried and I am excited. He doesn't have any identified handwriting issues. I was just thinking it would be good to work on since he'll be the youngest in his class. I think he is the school's first early K.
I sent his OT an e-mail asking about the program at the same time I posted here and she strongly recommended it. He sees her for integration of retained infant reflexes. Even though his OT is for other issues she thought he'd probably enjoy it. She also mentioned that the handwriting curriculum at the Montessori school he'll attend in the fall is a bit lacking so it will be good to supplement that area at home.
She even offered to help us get started once the materials arrive.
I am excited to do something more structured with him. I feel like I am dipping my toes in the homeschool pool!