Suggested resources to get you started:
Leonardo da Vinci at biography.com
Leonardo da Vinci: Anatomy of an Artist, Telegraph
The Theft That Made the Mona Lisa Famous, NPR
Treasures of the World: Mona Lisa, PBS
True Colors of the Mona Lisa Revealed, press release of Lumiere Technology's scan of the painting
Recent articles demonstrating Mona Lisa's fame:
'Mona Lisa' image goes to the moon and back, in successful NASA experiment, CNN
'Mona Lisa' model to be revealed by crypt?, CNN
Scientists unlock secret of Mona Lisa's face, CNN
Leonardo da Vinci's remains to be exhumed amid Mona Lisa self-portrait mystery, Telegraph
Woman attacks 'Mona Lisa', Telegraph