Conversations on Living, 2nd Series by J. Krishamurti and Gestalt Therapy: Excitement and Growth in the Human Personality, by Frederick S. Perls, as seen in Mad Men episode 713, "Person to Person".
Encore -- The milk and honey route; a handbook for hobos, by Dean Stiff [pseud.] With a comprehensive and unexpurgated glossary. Illustrated by Ernie Bushmiller.
Mad Men Season 7 Episode 13 was called "The Milk and Honey Route" which was the name of a 1931 "Handbook for Hobos" by Nels Anderson, written under the pseudonym Dean Stiff. Illustrated by Ernie Bushmiller of Nancy and Sluggo fame.
On the Road, by Jack Kerouac, Mad Men Season 7, Episode 12 ("Lost Horizon"). Don says. "Remember On The Road?" Bert replies, "I never read that book. You know that." Don says "I'm riding the rails." and Bert then quotes from the book: “Whither goest thou, America, in thy shiny car in the night?”
Mildred Pierce, by James M. Cain and The USA Trilogy, by John Dos Passos, Mad Men Season 7, Episode 8 ("Severance"). Roger said "Hey Mildred Pierce. Can I get the check?" referencing the novel by Cain. The waitress was reading the USA Trilogy. Mildred Pierce was a middle-class housewife who separated from her unemployed husband and supported herself and her children as a waitress.
In Mad Men Season 7 Episode 6 ("The Strategy") Pete, Peggy, and Don are at Burger Chef, where Peggy wants to shoot a commercial spot. "It's not a home," Pete says. Peggy replies, "It's better. It's a clean, well-lighted place." Pete replies, "Okay, Hemingway." http://www.nypl.org/blog/2012/02/27/mad-men-reading-list
A drunk Don Draper, with Newbery Award winning book Shadow of a Bull, by Maia Wojciechowska, on the couch. As seen in Mad Men Season 7 Episode 4, "The Monolith" http://www.nypl.org/blog/2012/02/27/mad-men-reading-list