Other sites that may be of interest:
Science
www.planetpals.com/earthday.html
www.fastplants.org
http://4hgarden.msu.edu/main.html
www.urbanext.uiuc.edu/gpe
http://aggie-horticulture.tamu.edu/kindergarden/kinder.htm
www.GardenGateMagazine.com/projects/kid.html
www.kidsgardening.com
http://www.uky.edu/Agriculture/Entomology/entfacts/misc/ef006.htm
Got it in you? 4H
Reading/Writing/Language Arts
Hooray for Diffendoofer Day! The Game
Social Studies
Pet Rescue Groups of Oregon and Washington
National Geographic Online: Site Index
National/Historical American Flags
Math
Algebra: grades 1-2 Algebra and Functions for
NRICH Primary Topics
Geometry