I always use Frank's The Americans when I teach photography classes. Sometimes students look at it blankly at first, sometimes they get a few ideas about working at the portfolio level (as opposed to the single-image level) and sometimes it sneaks up on them -- where they find they think about it later, while doing their own work.
Snapshots From the American Road
He didn’t seem interested in reflecting on why the book continues to have such an afterlife or why it has become a cultural touchstone, but chose instead to explain why it is still meaningful to him. “I’m very proud of this book because I followed my intuition,” he said, speaking with the clipped inflections of his native Swiss accent. He added that the idea of making a photographic chronicle of America wasn’t simply to take one picture at a time; it was a larger endeavor, “a matter of putting a book together the way I saw it.”