Here are a few suggestions for classic books that would be great additions to any design library:
"Decorating is Fun!" and "Entertaining is Fun!" by Dorothy Draper. What can I say? Draper was the consummate cheerleader of decorating- one who taught women (and I'm sure many men too) that a lovely home was accessible to everyone. All it took was ingenuity and enthusiasm. In addition to the witty prose, there is also a lot of practical advice that is still pertinent today.
"The Finest Rooms by America's Greatest Decorators" edited by Katherine Tweed. First published in 1964, this book contains essays by the top decorators of that time- Billy Baldwin, Mcmillen Inc., Rose Cumming, and Michael Taylor. Great photos too!
"Tiffany Table Settings", published in 1960. I love this book, especially as it was the book that started my collection. There are photos of table settings designed by socialites and decorators. Included are tables designed by Billy Baldwin, Van Day Truex, and Valerian Rybar.