This link takes teachers, parents and students to a variety of resources related to literacy. You have to click on a topic of interest and then a list of topics will appear and you select one.
Remember those "star charts" you had a kid, the ones where you earned stars for good behavior or doing your chores? Handipoints has taken the star chart concept and built a website on it. Here's how it works, parents (or teachers) create a list of items for their kids to do. The kids then check off each task as they do it. For each task or behavior goal completed the child earns points. When the child reaches their goal they can cash in their points toward playing the Handiland game. Parents/ teachers can also print the completed charts and provide offline rewards.
Shedd Aquarium in Chicago has a great collection of interactive learning activities. The activities are categorized according to grade level and vary in format. Some of the interactive activities are like video games (Squish the Fish for 1st graders) while others are more like virtual scavenger hunts (Conservation Investigation). The games and virtual scavenger hunts could easily take students an hour or longer to complete and the students would learn something new throughout the activity. In addition to the interactive activities, Shedd Aquarium provides a host of great Marine Science lesson plans for grades K-12.
Learning Games for Kids offers games for mathematics as well as many other content areas. Most of the games on Learning Games for Kids can be played directly on the website although some do link out to other sources.
Learn With Math Games is a site that I like because it offers online games as well as PDF templates for games that teachers and students can play in their classrooms. Learn With Math Games is organized by grade level and by mathematics topic.
Smarty Games features games for developing basic mathematics and reading skills. There are six mathematics games covering basic addition, subtraction, multiplication, and division. The reading section has two alphabet games and nine animated stories. In addition to the mathematics and reading activities, Smarty Games offers activities for learning to read a clock, puzzles, mazes, coloring activities.
"Educate your pupils using ARKive's many thousands of videos, images and fact files in a wide range of science, ICT, art and English projects. Use the ARKive multimedia materials to engage your class in key biology topics, such as variation and adaptation, habitats or life cycles, or use them as creative inspiration for art & design projects. All our photos, video clips and authenticated fact files are free and easy to use in your classroom activities and presentations."
NumberNut.com is a part of Rader's family of educational games and activities. Number Nut provides some great games with which students can practice and develop their math skills. Unlike many other Math game websites, Number Nut includes some word problems that force students to problem solve rather than just recall information from rote memorization.
Share my lesson has lesson resources for teacher from over 50 content partners. It is free and you can search for content by subject, and grade level. Lots and lots of resources for free.