Galaxies
Links
Arp's Catalog Of Peculiar Galaxies
http://members.aol.com/arpgalaxy/
Catalog of peculiar galaxy views with supporting material for amateur astronomers.
Cambridge Cosmology: Galaxies
http://www.damtp.cam.ac.uk/user/gr/public/gal_home.html
Background and images.
Classifying Galaxies
http://www.smv.org/hastings/galaxy.htm
Includes pictures and a lesson for learning Hubble's system of classification.
Galaxies Galore, Games, and More
http://amazing-space.stsci.edu/resources/explorations/galaxies-galore/
Includes a number of interactive games for learning about galaxies.