Biography and Genealogy Master Index (BGMI) is a database that tells you where to find information on over 13 million individuals, both living and deceased, in who's whos, encyclopedias, literary criticism, and indexes (but not in journal articles or books focusing on an individual, except through its indexing of Biography Index entries).
Below are some of the major resources that provide a way to search for biographies and then see the full-text (and images, when available) of the information about the person you found in your search. The tabs above will tell you about other resources you can use to find biographical information.