Once every year, the Perseid meteor shower returns. Each year, the Perseids are an excellent meteor shower, and are possibly the most popular meteor shower (they're definitely my favorite). They are often very fast and bright, and can sometimes leave fiery trails in the sky.
The Perseids are called so because of their apparent origin, called the radiant, in Perseus. Each meteor you see is actually a piece of the comet Swift-Tuttle. This comet leaves behind a trail of dust and debris every time it orbits the sun, thus refreshing the source of the Perseid meteor shower. This year's Perseid meteor shower will be at its most active peak on the night of August 12th, 2010.
The Perseids can be viewed any time between now and the 24th, however, since their peak is so broad. Look to the North and Northeast to see the most meteors. This year's shower also has the benefit of having very little interference from the Moon. The best time to watch the meteor shower is after midnight, as the Earth is rotating into the shower in the predawn hours. This will increase the meteor rate considerably.
With good, dark skies (after the moon sets at about 10 PM), expect up to 100 meteors per hour. Of course, light pollution and moonlight may decrease your observed meteor count.