The brand new Harper's Magazine has a wonderful article on The Prelinger library in San Francisco.

A world in three aisles:

Browsing the post-digital library

by Gideon Lewis-Kraus

You'll have to get it from Academic Search or similar DB that has Harper's but it is stimulating to see how they think about classifying their library.
Rick Prelinger is involved in the Internet Archive with Brewster Kahle so he is both bleeding edge techie and very old school with his library.
Richard