News

APOD—Astronomy Picture of the Day
NASA News—news releases from NASA
Space.com—current space related news

Tools

NASA Astrophysics Data System —search for journal articles, online catalogs, and libraries
Space Telescope Digitized Sky Survey—the Palomar Sky Survey digitized with HST fields too!
SkyView Virtual Observatory—generate images of any part of the sky in many wavelengths
U.S. Naval Observatory Time Service
SIMBAD on the Web
NASA/IPAC Extragalactic Database (NED)
AAS Job Registry
American Institute of Physics Career Services

Local Sidereal Time calculator
Hourly Airmass Table calculations
Astronomical Sky Calendar—calculates sunrise, sunset, twilight times, and moons position
Moon phase calculator
Planetary position calculator

Weather

National Weather Service Forecast
Weather.com
Clear Sky Clock for Van Vleck Observatory—this is a computer model predictor of the sky.

Organizations

American Astronomical Society
The Astronomical Society of the Pacific
Astronomical Society of Greater Hartford
Students for the Exploration and Development of Space (SEDS)
Space Telescope Science Institute