White House for Kids http://www.whitehouse.gov/kids/whlife/index.html
National Geographic for Kids http://www.nationalgeographic.com/kids/
Ben's Guide to Government for Kids - Excellent for 4th Grade Social Studies. Here you will find the 3 Branches of Government, Articles of Confederation and much more! http://bensguide.gpo.gov/3-5/index.html
Grammar Blast - A Fun, On-line Game http://www.eduplace.com/cgi-bin/hme-quiz-directions.cgi?Grade=4&Unit=1&Topic=The+Sentence
For Help in Telling TIME - This is a fun, interactive game http://teacher.scholastic.com/teachingstrategies/homework.htm
For help with Math - This is a library of virual manipulatives. Very cool! http://nlvm.usu.edu/en/nav/vlibrary.html