http://cybersleuth-kids.com

http://www.nettrekker.com

http://www.ajkids.com

http://www.awesomelibrary.org

http://tekmom.com
excellent - goes to other engines

http://www.kidsclick.org

http://www.aolatschool.com/students

In Spanish

http://espanol.paraninos.yahoo.com

http://mx.yahoo.com