Sarah Blackwell. At the existentialist cafe.

The well-written book tells you next to nothing about existentialist philosophy and its influence on XX century culture but plenty about the characters involved. One sentence: "It is the single documented example I have come across of Heidegger actually doing something nice" (asking a bookseller to prominently display Paul Celan's book before his visit to town) is worth the price of admission.

P.S. Now you understand where James Dean comes from.