Many of these excellent resources were found in this article published in ECRP:
Engineering Curricula in Early Education: Describing the Landscape of Open Resources (Bagiati, Yoon, Evangelou, & Ngambeki)
Science.gov
A gateway to government science information
Decoded Science
Science news written by scientists, but for a general audience
Encyclopedia of Life
Scientific knowledge about all living things
National Science Digital Library
Online portal for education and research on learning in STEM
Science Daily
Breaking science news and articles
Science News
Bi-weekly magazine of The Society for Science & the Public
National Geographic
One of the largest non-profit scientific and educational institutions in the world
Smithsonian Insider: Science & Nature
Examines many complex and time-sensitive problems
Museum of Science and Industry
The largest science museum in the Western Hemisphere
NOVA
PBS's highest rated science series on television
Science Friday Online
A weekly science talk show from NPR
Evolution
Comprehensive PBS site
Understanding Evolution
Multimedia resource from Berkeley
Animal Diversity Web
From the University of Michigan Museum of Zoology
NOAA
National Oceanic and Atmospheric Administration
MIT Technology Review
Analyzes the impacts of emerging technologies