A short lesson on asteroids

 Asteroid Impacts - AAAS/Subaru Prize website

Women In Science

 NASA's Reach Across the Stars website lets you learn more about female scientist and has cool downloadables and videos. 

The Lowell Observatory

Informative site of The Lowell Observatory where you can sign up for astronomy alerts and see what kid-friendly offerings they have.

Black Holes explained

http://hubblesite.org/explore_astronomy/black_holes/ - always a fascinating topic

Windows to the Universe

Windows to the Universe...cool astronomy stuff!

Science News for Kids

Science News for Kids has a range of articles on topics from Agriculture to Weather.  Age range is approximately 8 to 16.

Intro course to astronomy

Introductory Astronomy course from Calspace

plus the catalog of other courses

Cosmic Journey

A History of Scientific Cosmology

NASA Kids' Club

NASA Kids' Club...I think that says it all, doesn't it? ;)

Free curriculum tools from NASA

for educators teaching astronomy: http://astrophysics.gsfc.nasa.gov/outreach/educators.php

Two posts on gorgeous Hubble image

From Examiner.com and the Bad Astronomy blog.

Vote where Hubble should point!

http://blogs.discovermagazine.com/badastronomy/2009/01/28/you-can-help-point-hubble/

Super Neptune Caught by Small Telescopes

http://blogs.discovermagazine.com/badastronomy/2009/01/26/super-neptune-caught-by-small-telescopes/