Most weather sites have astronomy information, including the Weather Underground.
You can print a monthly star chart at Skymaps.com.
Create your own sky charts with SkyChart / Cartes du Ciel
Stellararium is a nice, basic freeware planetarium program.
Some paid programs: Sky Safari, Starry Night and The Sky. Different versions are available from inexpensive basic star maps to expensive control-your-telescope and view the universe from anywhere.
Although it's a bit old, Sky & Telescope's list of software is a good starting point if none of the above suit you.
The 100 brightest stars.
The Interactive NGC site.
The sky this week and Sun and Moon rise and set times for a single day from the USNO.
Satellites (be sure to set your location, and check out the Iridium Flares!)
My blog entry on buying a telescope
Cloudy Nights Telescope Reviews
Sherzer Observatory and the Astronomy Club at Eastern Michigan University.
The Student Astronomical Society of the University of Michigan.
The University of Michigan Lowbrow Astronomers.