What do you think are the standard US hospitality rules?

When it comes to receiving a friend or relative in your house, what are the rules or proper etiquette? I mean are there any? So far, what I have observed is just "here are the keys to the house, the car, make yourself at home, let's meet to share a couple of fun things to do together". Does this sums it all up or is there a given set of American rules/etiquette when visiting or having someone visit the house?