Enchantedlearning.com: A great website with resources for all curricular areas!
Educationworld.com: A great lesson planning resource
Mr.Donn.org: The BEST social studies website with lesson plans for all elementary grades
funbrain.com: An academic arcade style website
softschools.com: Useful academic printables
abcteach.com: Reources for all of your curricular, holiday, seasonal or monthly needs!
starfall.com: a wonderful language arts based resource for primary grades
aplusmath.com: Another great math resource website
activityvillage.co.uk: coloring pages, home school resources, educational resources, kids crafts, puzzles, printables,