MCM design books  

my favorite.....
Ultra modern midcentury design.....definitely ULTRA
Search "Googie"

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Second hand and published in the day are more interesting than much of what is published now, the photographs are often black and white and there is more text but the writing is usually better and the details and more obscure information is very enjoyable.

Agree
with Heath. Search garage sales, flea markets, etc. for out-of-print design books.

Quite right,
Heath. The earlier the better, in my experience. The main advantage of newer books is color; the disadvantage in misinformation, or no information -- and you never know what's been refinished.

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The books I mentioned in another thread (there were more good purchases that day) are wonderful, something like Ronchamp is discussed in much better detail, the entrances, the doors by the man himself and the back of the building etc, in anything now you'd get a few big (admitedly good)images or some po mo claptrap.
Contemporary photographs of interiors are great, they can help authenticate paintings and all sorts of other historical details.
I think there is a new edition of Modern Architecture a Critical History by Frampton out and I don't think Space Time and Architecture by Geideon has ever gone out of print.

Thank you for the suggestions...
Thank you for the suggestions, and I will do that!