Is it truly room and board or is he just helping out with bills? Do you have a landlord/tenant relationship?
If he is your tenant, you would enter the income on Schedule E and say that you rent out part of your home. You would prorate by square footage the portion of the home that he rents vs the square footage of the entire home.
Shared spaces are considered the homeowner's personal-use property and is not included in the rental square footage.
