Who Will Explain Today's Stock Market To Us Idiots?

So the Dow is way down today. The Times says it's a "crunch in the American credit market." That's not a very helpful turn of phrase! But even we know that trading on the NYSE has been weird—peak volumes, stuff going on—and like, something about mortages and the like that pissed off Jim Cramer. Also job cuts and stuff? How does this fit together? Without using phrases like "subprime crisis," can someone explain to me 1. What's going to happen to those of us who tucked our wee savings in the stock market and 2. Are any of you ever going to be able to buy a brownstone in Brooklyn? Show your math!