Dictionary of American Biography E176.D653. Authors writing in English Oxford Companion to English Literature PR19.D73. Entries range from a paragraph to two pages. It's worth looking through the different editions of this fine work as the authors who are included vary from edition to edition. British Authors series PR451.K8.
Various volumes cover different time periods.
Entries range from a half page to eight or more. Twentieth Century Literary Criticism PN771.T9. Covers authors who died between 1900 and 1960.The index to the most recent volume contains references to entries in the entire set. Short biographies precede critical information. The best biographical information is usually found in the first volume covering the author in question.