For years I've been meaning to do a book on barns, and have quite a collection of barn books. (This isn't all of them.)
I just discovered a drop-dead book of barn photos. I read it in bed last night and ended up putting about 20 markers in on pages with beautiful photos.
It's Hand Raised: The Barns of Montana, by Chere Justo & Christine W.Brown, with photos by Tom Ferris. It's the best barn book I've ever seen (and all these barns are in the state of Montana!). See: http://shltr.net/tomsbarns for lots of photos from the book.