Toys from trash Simple science activities using low cost resources by Arvind Gupata and his team.
CS Unplugged A collection of free teaching material that teaches Computer Science through engaging games and puzzles that use cards, string, crayons and lots of running around.
STEP The STEP Science Program was initiated by Peace Corps Volunteers in mid 1960s, who created amazing resources to teach science to students from grades 6 through 10. The activities are still relevant to introducing science concepts.
Maker Tour MakerTour provides an extensive list of makerspaces and maker communities around the world. Search for communities in your areas to promote local collaboration.
Instructables Explore, discover and share DIY resources for almost everything.
Exploratorium Very useful science, engineering and making resources and well explained activities for students.
Brainstorming and Ideation Here is a post that is useful if you are starting a new project. The brainstorming techniques mentioned will help you come up with creative ideas for your projects.