City University of New York
History of Chemistry
A great site that has a detailed biography of John Dalton, and illustrations of his original chemical symbols.
Wikimedia
Wikipedia: John Dalton
This site contains the biography and other related links about John Dalton.
Soylent Communications
John Dalton
A very thorough biography of John Dalton on this site made by Notable Names Database. Also gives the names of books that were written about him or his ideas.
Other
Dalton's Atomic Theory
This site contains Dalton's atomic theory and a brief biography about the scientist.