Many great books out there as mentioned in this thread. However my top two a

1. "The Art of Soaring Flight" by my Dad's friend, Wolf Hirth (1938.)

2. "Kronfeld On Gliding and Soaring"
subtitled "The Story of Motorless Human Flight" by Robert Kronfeld (1933.)

I'm told that only 500 copies of Robert Kronfeld's book were translated into english. I have two extra copies to sell someday, perhaps at the International Vintage Sailplane Meet (IVSM) on Harris Hill near Elmira, NY, July 9 - 16, 2016. I need to thin out my huge collection of vintage books and memorabilia. I'll probably publish an inventory sometime this year before auctioning on eBay.

There is something unique about the "old school" books. Soaring pilot-authors of the 1929-1969 era seemed in touch with the sky and very much one with the sailplane. They understood and shared the magic of soaring flight and how to read the sky. Indeed, the "Art" of soaring.

Later, pellet variometers and the "Memphis" rate of climb instrument were among the best available. One of those and a road map got you soaring cross-country. If you ever get a chance, smell a wooden sailplane and you will sense the magic. As one of the "soaring kids" of the 1960's I'm so glad that I saw the final decade of that era.