Here is something very cool from NASA. It simulates what the Sun will look like on August 21. "Eyes on the Eclipse" lets you explore different locations along the path of totality and where there will be a partial eclipse, or no eclipse.
If you're in California on August 21, you're not on the eclipse line of totality, but there will be some good partial eclipses. Get your eclipse glasses NOW - or be sure you know how to project the eclipse. (I saw a picture of someone using a colander to project multiple images, but I've never tried it myself!)
I came across this article from the St. Louis Post-Dispatch, and liked its list of things to look for during a total eclipse. An eclipse is more interesting than just looking at a big black spot where the Sun should be. (That can actually be somewhat disturbing.)
While World War I was tearing Europe apart in 1915, a German physicist presented a theory that would shake up the way we see the Universe. The physicist was Albert Einstein, his face still unknown to the world, his name not yet a synonym for genius. How did a solar eclipse in 1919 change all that?