I love design and lifestyle books, both current ones and those that are out-of-print. I am constantly looking for new ones to add to my library- the only problem is trying to find space to store all of my books!
Here are some suggestions for books to add to your design library:
Jansen by James Archer Abbott. Maison Jansen was one of the best known design firms of the 20th c. A great anthology of their work.
Van Day Truex by Adam Lewis. While Truex is best known as the former Design Director at Tiffany & Co. (he designed the classic Bamboo flatware pattern, among others), he was also an instructor at Parsons for many years . Truex also famously introduced Albert Hadley to Sister Parish, and the rest is history!
And, one out-of-print suggestion:
"My Favorite Things; A Personal Guide to Decorating and Entertaining" by Dorothy Rodgers. This is a really fun work written by the wife of composer Richard Rodgers. Includes tips for decorating one's city and country homes, entertaining guests in one's home, and generally living a swell life. Includes classic recipes such as Jellied Madrilene(!).