Find book-length biographies in the library by searching the catalog  "biography" as a subject.  Add additional terms to limit your search, for example:  biography AND politicians.

Numerous encyclopedias, dictionaries, and other resources are listed in the catalog which include biographies.  For example:

Biography AND indexes

Biography AND dictionaries

Biography AND encyclopedias

Modify these searches to limit results by topic or by ebook.

The African American National Biography  (Ref. E 195.96 .A4466 2008)

Amiercan National Biography (Ref. CT 213 .A68 1999)

Appleton's Cyclopaedia of American Biography (Ref. E 176 .A65)

Current Biography Yearbook  (Ref. CT 100 .C8)

Dictionary of American Biography (E 176.D562)

Dictionary of American Catholic Biography (Ref. U52 .D53 1984)

Dictionary of National Biography (DA 28.D4)

Encyclopedia Judaica (Theology Ref. DS 102.8 .E496 2007)  3 vols.

International Who's Who  (Ref. CT 120 .I5)