Astrospheric Astronomy Weather App
The Astrospheric is a real time resource available as an APP on most app stores, showing factors such as clouds and humidity that affect observing, arranged by time of day.
Sky Charts/Maps and Object Lists
There are a wealth of online references for the amateur astronomer. Here are a few to get you started.
Astrospheric- The Sky Tonight
Monthly Star Chart
Astronomy and Astrophysics in the New Millennium
SEDS Messier Catalog
Interactive Messier Catalog
SEDS NGC Catalog
Interactive NGC Catalog Online
SBIG Astronomical Instrument
The STScI Digitized Sky Survey