A solar eclipse occurs when moon passes between the sun and the Earth, causing a shadow to fall on the the surface of the Earth. The photograph at the right is a solar eclipse for 2008 (Image from NASA).
Of course, you should never look at the sun directly. The Stanford Solar Center has information on how to make a "pinhole camera" or solar projector to view the sun indirectly.
This video explains more about tomorrow's eclipse:
If you miss this one, don't worry. You can check NASA for future eclipses. There will be a total solar eclipse passing over the middle of the United States in 2017.
I'd love to hear from you if you get a chance to view it. Do you see any of the shadows they show in the video? We'll probably be able to see a partial eclipse where we live.
This book lists were you can find solar eclipses through the year 2017:
You'll need something like this for proper viewing: