Six Poems: A small selection of Williams' poems, from the August 1920 edition of The Dial; notable because it includes photographic reproductions online in JPEG format of the original Dial pages.
William C. Williams: Life and works of William Carlos Williams.
William Carlos Williams: Apparently there's a band named after Williams. This is their site.
William Carlos Williams: An introduction to the poet by Professor Eiichi Hishikawa, Faculty of Letters, Kobe University.
William Carlos Williams: An Academy of American Poets "Poetry Exhibit," includes a brief biography, a selected bibliography, and a small selection of poems.
William Carlos Williams Review: Online scholarly journal devoted to Williams' work.
Williams, William Carlos: An interesting, slightly different perspective (from the NY School of Medicine's "Medical Humanities" website) of some of Williams' work--including brief annotations of "A Red Wheel Barrow" and "Complaint," as well as a few other poems and stories.