Shabbat VaEra

Parshat Vayera begins with the mysterious visit of three strangers to Abraham and Sarah's tent. From this story, we learn about the Jewish tradition of hachnasat orchim - welcoming guests. The Chofetz Chaim (Rabbi Yisrael Meir Hacohen Kagan, 1838-1933) comments: "The Torah explains at great length about the matter of how Abraham welcomed his guests, with all the details... we learn from this that the Torah intends to teach us to learn from the example of Abraham our forefather." (Ahavat Chessed, part 3, chapter 2)
Some of the Chofetz Chaim's advice on welcoming guests includes:When Abraham saw the strangers, he ran to greet them, and bowed down to them, and spoke softly to them - perhaps he could bring them into his house. ... We learn from this that we should seek out guests, and welcome them with great warmth, as if a great, rich person had come before us, from whom we could gain much.
Abraham understood that they did not intend to stay long and to be a burden to him, so he said 'Let me fetch a morsel of bread that you may refresh yourselves, then go on' (18:5). In the end, he made a feast in their honour, in the manner of one of those tzaddikim - righteous people - who says little and does much.
When guests come to someone's house, he should welcome them with a happy face, and should immediately give them something to eat - because perhaps the guest is poor, and is embarrassed to ask. He should welcome the guest with a glad countenance - not an angry face - and if he has worries, he should not show these on his face. He should appear to his guests as somebody wealthy - even if he is poor - and speak in a comforting way, because this will help the guests to relax.
The host should cut the bread into slices front of the guest, so that his guest will not be embarrassed or ashamed to help himself. And even more so, he should not look into his guest's face while he is eating, so as not to make him feel self-conscious.
Modern sources - Jewish and non-Jewish - continue to offer advice on welcoming guests. Some contemporary tips include:
Make sure that your guest's room is clutter free and has some privacy. "If you've read a wonderful novel, share it with your guest. Five-minute mysteries, travel books, an assortment of magazines, classic novels, or the local paper will provide quiet-time activities for your guest." (About.com)
Make extra pillows and blankets available so that your guest doesn't have to ask for them. A reading lamp, a hairdryer, clothes hangers, an alarm clock, a bathrobe and slippers can all help make your guest's stay more comfortable. Arrange the space in the guest room to include a chair, some storage space and a desk area for your guest to use, particularly if they will be staying for a long time.
-D'var Torah from Limud LA