Frederick Lewis Allen's informal history Only Yesterday, published originally in 1931 and reprinted often since, is a wonderfully informative and easily read account of the era. It should be available in most libraries.

Arthur F. Kinney's Dorothy Parker, Revised (1998) is highly informative, with biographical and critical insights. There is also a previous, unrevised volume, published in 1973.

Since Parker's life and reputation were a big part of her fame, looking into a biography sheds light on the writer. Marion Meade's biography, Dorothy Parker: What Fresh Hell Is This? (1988) is an easy read.

The Portable Dorothy Parker (1973) is a standard collection that includes short stories, poetry, and newspaper reviews written by Parker. This is probably the best single-volume source of her work, and it is easy to locate.

Rhonda Pettit's A Gendered Collision: Sentimentalism and Modernism in Dorothy Parker's Poetry and Fiction (2000) may...