We use to host the chapters here on the site, but (via Project Gutenberg) has the books available and in multiple formats.

View the Barsoom series' Wiki entry for more details on Publishers, dates and other details.

Below are links to each book and in their proper order:

  A Princess of Mars
February–July 1912
  The Gods of Mars
January–May 1913
  The Warlord of Mars
December 1913-March 1914
  Thuvia, Maid of Mars
April 1916
  The Chessmen of Mars
February–March 1922
  The Master Mind of Mars
July 15, 1927
  A Fighting Man of Mars
April–September, 1930
  Swords of Mars
November 1934-April 1935
  Synthetic Men of Mars
January–February 1939
  Llana of Gathol
March–October 1941
  John Carter and the Giant of Mars
(Contained in 'John Carter of Mars')
January 1941 (Written by John Coleman Burroughs)
  Skeleton Men of Jupiter
(Contained in 'John Carter of Mars')
February 1943

Glossary of Names and Terms used in the Martian books