The Library of Congress has posted a site on the women's suffrage movement entitled "Women of Protest: Photographs from the Records of the National Woman's Party." Along with images and a timeline, there are essays on the NWP and its tactics.
Students and teachers may find this a useful place to begin their research. Bibliographies of primary and secondary sources, as well as annotated timelines, are among the resources available here.
The Smithsonian maintains a site on teaching women's history. It offers biographies and images of women in politics, science, and the arts.