A total solar eclipse will be the most awesome astronomical experience in your life. However, the Sun can be dangerous to your eyes if you do not take precautions. You can only safely observe the eclipse during totality! At any other time, you MUST use eye protection.
Even during the eclipse when the Sun is 99% covered, the remaining part of the Sun is still bright enough to damage your eyes (without pain, which makes it even worse). People mostly affected by retina burns during eclipses are very young chidren or young adults. One can safely observe the Sun through projection of the Sun via a telescope or pin hole camera onto a screen, or by using a solar filter on a telescope.
However the most common and recommended technique that people use is eclipse glasses (pictured to the right). These block all of the dangerous wavelengths of light and most of the visible light too. They are a cheap and safe solution for observing the Sun during the partial phases of the eclipse.
Where to buy? The AAS has some good resources for glasses here or the William M. Starkel Planetarium is selling them for $1/each, which is a great deal. We also suggest Solar Eclipse International, which provided us with some educational outreach glasses!
For young children, the more safe option (preventing any accidental stares into the Sun) is to make your own pinhole camera. We have a nice tutorial on how to make and use your own pinhole camera using supplies around the house: Pinhole Camera.