I used these books to find out about Earthquakes:
Plate Tectonics
by Alvin, Virginia and Laura Silverstein
Atlas of Geology and Land Forms
by Cally Oldershaw
Friend or Foe
by William Muñoz
Website:
http://earthquake.usgs.gov/4kids
RESOURCES
Earthquake "Where and When"
Earthquake "Personal Safety"
Earthquake Resources
Earthquake Photo Gallery
Earthquake Activities