SpaceWeather.com says the Perseid meteor shower has already begun, although it won't be at its peak until August 12. This is especially good news for people who live (or can get) away from the bright lights of the city. Night owls and early risers (in the dark before the crack of dawn) have the best chance of seeing the meteors.
The source of the shower is Comet Swift-Tuttle. Although the comet is nowhere near Earth, the comet's tail does intersect Earth's orbit. We glide through it every year in August. Tiny bits of comet dust hit Earth's atmosphere traveling 132,000 mph. At that speed, even a smidgen of dust makes a vivid streak of light--a meteor--when it disintegrates. Because Swift-Tuttle's meteors fly out of the constellation Perseus, they are called "Perseids."
This year's show is expected to be particulary good, because the meteor shower will be at its peak the same night as the new moon, so it will not be obscured by moonlight. So stay up late (or get up early), lie back, look up, and enjoy the show.
Here are some observing tips and more info on the Perseids. And a photo gallery of meteors already spotted (I like the one with a firefly). Plus, as a special bonus, SpaceWeather has this link to a story about the International Space Station astronauts observing meteor showers from above, complete with video.
Here is the sky map: