How do I add my son's name to the deed to my house. I want the house and its contents to pass to him upon my demise.

At the top of the Real Estate Law Forum there is a sticky post that explains how to add someone to your deed. You can read it at https://www.askmehelpdesk.com/real-estate-law/how-add-someone-your-deed-569716.html

However you should be aware that there may be tax and mortgage implications involved. You may want to write a will leaving the property to your son upon your passing instead. It would be a good idea to speak to an accountant or attorney before you make any changes to your deed.