Other
James K. Polk Memorial Association's Site
The James K. Polk Memorial Association has compiled a thorough guide to his life which includes many pictures.
The White House
The White House: Presidents: James Polk
Short biography of James K. Polk, 11th President of the United States. Includes a color portrait.
Library of Congress
Loc: Biographical Directory of the u.s. Congress: James Polk
The U.S. Congress site from the Biographical Directory contains a brief summary of the life of James Polk complete with a picture.
PBS
James Knox Polk 1795 1849
This brief summary covers major aspects of Polk's presidency, including his support of Andrew Jackson's policies.