TeachersFirst is a free, advertising-free teacher resource web site offered as a service to teachers by The Source for Learning, a non-profit learning and technologies corporation. Their value-added reviews and teacher-friendly site have been helping teachers since 1998, sharing the best of the web and their own original content along with practical implementation ideas and best practices for effective integration of technology as a tool for teaching and learning.

KutaSoftware.com provides users with simple yet effect math worksheets for free!
This site also features test and worksheet generators and various free trials for math instructors.

9000+ downloadable teaching materials, eBooks, educational videos, 
interactive activities, PowerPoints and more.

At this site kids can learn all about fractions. Kids, their parents and teachers can print 
all lessons and fractions worksheets free of cost.

I realize that this site appears to be a little outdated and that several worksheets take multiple reloads, 
but if you are patient, you might just find the perfect 
worksheet or review you were looking for. 

Review and learn several free educational games involving addition, 
subtraction, multiplication, division, English, and science.

Checkout how EduKate and Inspire used a $0.99 iPhone app called AgingBooth to show how students will look at 100 years old. This will be awesome to do for 100th day of school!

Games Galore!
Fun and free educational games for kids in K-8. Featuring multi-player learning games, math games, language arts games, and much more!

MIT OpenCourseWare is a web-based publication of virtually all MIT course content. OCW is open and available to the world and is a permanent MIT activity.

Khan Academy is a non-profit educational website. Learn for free about math, art, computer programming, economics, physics, chemistry, biology, medicine, finance, history, and more. 

Have you or your students ever wondered what they would look like as a Wimpy Kid character? 
Now's your chance to find out!