http://www.fordham.edu/halsall/mod/1497vespucci-america.html
original letter about his first voyage.
http://www.millersv.edu/~columbus/papers/canaday.html
biography of Vespucci
http://www.studyworld.com/Amerigo_Vespucci.htm
another short biography
http://www.straightdope.com/classics/a4_021.html
Why is America named after Amerigo?
http://www.auburn.edu/~downejm/sp/dkv/Amerigo%20Vespucci.htm
Picture and knowledge he needed for the voyage.
http://www.esd.k12.ca.us/Matsumoto/TM30/history/Explorers/vesp.html
Readable biography with pictures of his ship and a map of his route.