Starting with the Sunrise
Imagery is available on the Internet 24-hours a day and sunrise is an excellent option for displaying the unique properties of visible imagery.

You can view 30 minute interval visible images of North America at
http://www.ssec.wisc.edu/data/east/animation/goeseastvis.html
and 3-hour intervals of the western hemisphere at
http://www.ssec.wisc.edu/data/geo/
Click on "Full Disk", "Visible" & "animate"

Understanding abbreviations in the captions of satellite images
Captions on most satellite images indicate the date, time, satellite and type of image.
Here's an example:   GOES 12 WV FOR 17 FEB 07 AT 19:15 UTC

GOES 12 = Geostationary Orbiting Earth Satellite 12 (operational satellites are numbered)
WV = Water Vapor Channel (VIS = Visible, IR = Infrared)
17 FEB 07 = February 17th, 2007
19:15 UTC = 19:15 Coordinated Universal Time
Coordinated Universal Time (UTC) is the local time at Greenwich-England, which is at 0° longitude. Satellite images and other weather observations are recorded in UTC so scientists can refer to a global time frame. You can convert UTC to local time zones in the U.S. by subtracting one hour for every 15 degrees longitude.

Images with Explanatory Text
There are a few sites on the Internet that combine imagery with explanations. Three excellent resources are NASA's Earth Observatory, CIMSS Satellite Blog, and NOAA's Image of the Day.

NASA Earth Observatory Image of the Day combines images of Earth with explanatory text geared towards educators and the general public.
CIMSS Satellite Blog features satellite imagery relevant to current weather events accompanied by explanatory text that is a bit more technical than the Earth Observatory and geared more towards forecasters, researchers and college-level educators.
NOAA's Image of the Day showcases a significant environmental event every day accompanied by a geographical reference inset map.