I thought that would get a reply!
Ferenc Mate's books " The Best Boats to Build or Buy" that has boats like Pacific Seacraft, Hallberg Rassy, Swan, and many others and shows how they are built.
Books by designers like Robert Perry showing his designs with commentary about why he did what he did.
Designs of Bill Garden volumes 1 and 2
New book (coming out next month) buy Chuck Paine about his designs
The View from the Helm » 2010 » March
Offshore and Further offshore by John Illingworth
The Proper Yacht by Robert Beiser
Steve Dashew's books - Offshore Cruising Encyclopedia Volumes 1 & 2
These are the books and others like them that taught me about yacht design, not just about which boat to choose, but describing why a boat is shaped the way it is.