Caltech Outreach
This site gives a large number of categorised Educational Astronomy links and is an outreach activity by the Communications and Education (ICE) team of the "Infrared Processing & Analysis Center" (IPAC).  Go here

SKA for educators
Outreach and Education resources by the "Square Kilometre Array" (SKA) team.  Go here

ASP Education and Outreach
The Astronomical Society of the Pacific (ASP) has a comprehensive collection of resources and information for teachers and students as regards teaching and learning Astronomy. Go here.

ClassAction modules
by the University of Nebraska-Lincoln, consist of questions and resources designed to encourage student engagement in the classroom. More details can be found on the overview: how to use and the pedagogy behind, the pages. The PowerPoint page gives some guidance on importing ClassAction resources into PowerPoint. The modules listed roughly follow the outline of most introductory astronomy textbooks. ClassAction is still being actively developed, so some topics are covered more thoroughly than others. Go here

The Nebraska Astronomy Applet Project
also by the University of Nebraska-Lincoln University, provides online laboratories targeting the undergraduate astronomy audience. Each lab consists of background materials and one or more simulators that students use as they work through a student guide. Pre-tests and post-tests can be used to gauge student learning. These are awesome modules, several of which we use ourselves regularly in our courses. Go here

Educational Resources for Astronomy 101
This is a collection of digital resources by AstronomyCenter.org, for college-level introductory astronomy faculty and students. Astronomy Center is brought to you by the American Association of Physics Teachers, and the National Science Digital Library. Go here

CosmoLearning
is an educational website committed to improve the quality of homeschooling, teaching and student excellence, helping educators and self-learners alike anywhere in the world. Designed to work as a free home-school and organized according to traditional curriculum standards, CosmoLearning provides video lectures, courses, documentaries, books, quizzes, lecture notes and much more. This resource links to the Astronomy section. Go here

Planetary Size and Distance Comparison
What is the diameter and relative distance from the sun of each planet in our solar system?  This is one activity of many on this National Geographic site. For other activities search for “astronomy” or “space science” (bottom of the page). Go here

Silicon Valley Astronomy Lectures
Founded in 1999, the Silicon Valley Astronomy Lecture Series lectures are presented on six Wednesday evenings during each school year at Foothill College. Speakers over the years have included Nobel-prize winners, members of the National Academy of Sciences and many other well-known scientists explaining astronomical developments in everyday language. The series is currently organised by the SETI Institute. They are available on Youtube. Linked here is the playlist in reverse chronological order. Go here

Amazing Space
uses the Hubble Space Telescope's discoveries to inspire and educate about the wonders of our universe. Check out the tabs "Resources" (by topic or type). There is also a valuable section on "Homework Help". Go here

Royal Astronomical Society of Canada
The goal of the Education Committee of the Royal Astronomical Society of Canada is to help parents, teachers, students and the general public learn more about astronomy. In particular check out the category “Classroom Help” and "Extra Resources". Go here

ESA Education Office
The European Space Agency (ESA) has from its inception been focussed on supporting education in the area of space. Several in-resident activities are only available to ESA member states, but there is a wealth of resources, information and ideas on the ESA Education website. In the "Teacher's Corner" you will find classroom resources "Teach with Space" for primary and secondary level with guides and worksheet that can be downloaded.

Project CLEA
Contemporary Laboratory Experiences In Astronomy (CLEA) has developed laboratory exercises that illustrate modern astronomical techniques using digital data and colour images. They are suitable for high- school and college classes at all levels. Each CLEA laboratory exercise includes a dedicated computer program, a student manual, and a technical guide for the instructor. New resources are no longer developed but the website is still available for downloading existing material. Go here

UK Research and Innovation
The UK Research and Innovation section of the Science & Technology Facilities Council (STFC) has a Public Engagement component on its website with activities for the general public and for schools. It is generally oriented towards Science and Technology, Go here

How to use a planisphere
A planisphere is a portable, handy star chart that can be set to show the location of objects in the sky for any given date and time. Learn how to work with a planisphere here

ABC Science
ABC Science gives many links to the latest science news. The "Space" section is of interest for Astronomy and Space Science. Go here

Earth Learning Idea
contains an Innovative Earth-related collection of teaching ideas with free downloads of resources. Go here

HUBBLESITE Explore Astronomy
The universe holds many mysteries. Explore some of the marvels that lie within our cosmic neighbourhood and beyond. This site contains a section "Key Concepts" and various categories of astronomy topics. Go here

Science in School
is the European journal for science teachers. Its website has the tabs "Understand", "Inspire", "Teach" and an Archive of previous issues. Check out the "Astronomy / space" component in some of these tabs, listing topical articles in recent issues. Go here