Here is a great site I use that is meant for all K-12 grades. It is put out by the Smithsonian Libraries and has loads of resources (from articles to virtual exhibits to classroom resources.) The site is entitled Anthropology on the Internet for K-12 and can be found at http://www.sil.si.edu/SILPublications/Anthropology-K12/index.htm

K-12 Learning Objectives

K-12 Grade Ranges--Resources

Grades K-3

Grades 4-6

Grades 7-9

Grades 10-12