The Nine Planets: Ganymede
Overview with data, text, images, links.
http://www.seds.org/billa/tnp/ganymede.html

Hubble Finds Ozone on Jupiter's Moon Ganymede
Press release from the Space Telescope Science Institute.
http://oposite.stsci.edu/pubinfo/press-releases/95-36.txt

Solarviews.com: Ganimede
Statistics, animations and annotated pictures.
http://www.solarviews.com/eng/ganymede.htm