To find biographies and autobiographies in the Library catalog, do a subject search on the person's name, last name first.
You may see specific subheadings for authobiography or biography, but books filed simply under the subject's name will also have biographical information.
Look also for subheadings for archives, correspondence, diaries, family, friends and associates, homes and haunts, etc.
For example: MasterPlots Complete (CD-ROM) - MasterPlots Complete contains plot summaries, brief critical essays, author biographies for fiction, non-fiction, poetry, drama worldwide.