The following links are just a few I have found useful. I will continue to add more as I become aware of them. I try to avoid sites which advertise but will follow links to useful sites and add them here if they seem appropriate.
Multi - dicipline
bank of digital resources for teaching biology
Videos based on the elements and other chemical topics
Scientific Committee on Problems of the Environment
Integrated Risk Information System
A sight with a downloadable viewer to look at images of the sun