Leonardo Da Vinci Websites
Exploring Leonardo: http://www.mos.org/sln/Leonardo
A website about Leonardo's inventions and masterpieces as well as some brief information about his life.
Genius of Leonardo: http://www.geniusofleonardo.com/
The website of Piazza Signoria, a museum featuring many of Leonardo's machanical creations reproduced from his sketches and notes.
Leonardo Da Vinci: http://www.mos.org/leonardo/
This website has a good amount of information about leonardo's life and some original multimedia resources.