Here are a number of web sites that I truly enjoy and think would be helpful for you. As a teacher I have used these sites for years and find them irreplaceable. If anybody knows of some quality math sites out there, please share.
AgradeMath - Tons of math games and a really helpful math flashcard maker.
BJ Pinchbeck's Homework Helper - An extremely well curated web site that is filled with helpful reviews of extremely useful web sites.
CoolMath - Has a bunch of great tutorials. I really enjoy their stuff.
Crickweb - Provides access to a number of wonderful teacher resources and games for kids.
Free Math Help - An excellent math site geared more towards the secondary crowd. Filled with helpful lessons, calculators, and games.
Kid Info - Filled with resources for students and parents.
Marty Bucella - Walk into the wonderful world of Cartoonist and Humorous Illustrator Marty Bucella.
The Classroom - A great resource for any one involved in helping students learn.
The Classroom Kit - Features a number of wonderful resources for K-2 teachers.
Vertex 42 - An excellent series of downloadable MS Excel templates for teachers and students.
Word Games - Word Game Time offers word games, videos & worksheets for children. A great site for parents, teachers and kids to learn in a fun and engaging way.