awk, bless him! he is probably pretty scared at everything new around him... when i got Dexx (a 2.5?yr old chi) he hid in the bed for a fair while, but i lay on the floor near him (not starring at him though, that would also be scary) and any time he came near me i gave him a bit of boiled chicken breast... by the next day he was sleeping on my knee watching animal planet with me- when not playing with the puppies!
also, when dexx looked scarred, a soft, slightly higher pitched voice always seems to get his attention focused on happy thing a lot quicker than my ordinary voice, so that might help with your little boy?
you'll need to be patient, although i know you already know that; and just accept that he needs time to get used to people who actually want him there- you don't know what he has been through in his 8 years living with 'non-dog people'- love may be a whole new concept to him... did thwy give you much of a back story to him (although how much you can trust what they say is unknown)?
people like that should be strung up!
whats his name- you changing it? do you have pics?
and welcome to yorkietalk both of you!