Some biological links (which are also non-scientist-but-interested-person friendly):

MonarchWatch dedicated to the best-loved butterfly in the world.

Discover Life, which is still apparently under construction, but will someday be an online encyclopedia of information about all different taxa. It has links to areas where "ordinary folk" and scientists can get involved in trying to document the biodiversity in the U.S.

Frog Watch USA, a program dedicated to monitoring frog and toad populations across the U.S. Another place where nature-loving citizens can become involved.

and a "critical thinking" type resource: How Do You Know a Webpage Contains Good Information?, from Ithaca College (this link is going on the syllabus for all the classes I teach where students have to do research papers!)