Some good science sites listed here.
http://www.mtnbrook.k12.al.us/tech/science1.htm
Weather
http://inspire.ospi.wednet.edu:8001/curric/weather/weather.html
Clouds
http://inspire.ospi.wednet.edu:8001/curric/weather/pricloud/index.html
Seasons
http://www.urbanext.uiuc.edu/fallcolor/trees.html
Animals
http://www.photolib.noaa.gov/animals/index.html
Farm animal sounds
http://www.davisfarmland.com/fun/funsound.htm
Growth & reproduction
http://msichicago.org/exhibit/chick/chick.html