Here are some fantastic science programs for families. Each site lists various programs for age groups.
The Maritime Aquarium at Norwalk:
This aquarium has created marine science lessons; some are for kids of all ages while others target specific grades.
USGS Science Explorer:
Find loads of science lessons in this topical directory by the US Geological Survey.
Center for Interactive Learning and Collaboration:
This site offers daily free, interactive, live-streamed programs for kids in grades K-6. Programs come from universities, zoos, aquariums, museums, authors, and more!