Time and Date

• Official US Time (PST) - NIST & USNO
• U.S. Time Zones (Universal Time Conversion) - USNO
• World Time Zones (PDF) - USNO
• Julian Date Converter - USNO

Sun and Moon

• 2003 Moon Rise and Set Table - USNO
• 2003 Sun Rise and Set Table - USNO
• 2003 Astronomical Twilight Table - USNO
• Today's Lunar Data - Heavens Above
• Lunar Disk Illumination - USNO

Location

• Compute Values of Earth's Magnetic Field - NOAA

Observation Information:

• Current Constellation Map of the Sky - Heavens Above
• Current Solar System Planet Locations - Heavens Above
• The Constellations - Heavens Above
• Planet Summary Information - Heavens Above

Satellites and Minor Planets:

• International Space Station Visible Passes - Heavens Above
• Hubble Telescope Visible Passes - Heavens Above
• Minor Planet Information - Heavens Above
• Near Earth Object Passes - NASA / JPL

Visual Observing Aids:

• Telescope Eyepiece Simulator - Matt Wier

On-line Magazines:

• Sky and Telescope Magazine - My favorite website for amateur astronomy.
• Astronomy Magazine - Another resource for interesting astronomy topics.

On-line Educational Resources:

• Students for the Exploration and Development of Space - This is a very good website for raw information.
• StarDate Online - Very useful information from The University of Texas McDonald Observatory.
• Heavens Above - Information on satellites or astronomy.

Misc. Interesting Websites:

• Astronomy Picture of the Day - A great bookmark, learn something new everyday.

Observatories:

• Hubblesite.org - Home of the Hubble Space Telescope.

CCD Educational Resources:

• Ron Wodaski's Website - Buy his book, it taught me everything.