There's nothing more frustrating than bad manners. Originally published in 1948 and written by Millicent Fenwick, Vogue's Book of Etiquette is a must-read if you need tips for proper decor when it comes to:
* furnishing/decorating a house and making guests feel welcome
* cocktail party planning
* formal entertaining
* letter writing
It's full of guidelines on these topics and so much more. I find myself using it as a reference time and time again. eBay has a few copies listed for sale here.