For best viewing, look toward the eastern sky before dawn early Friday morning. The meteors will appear to be coming out of the Leo constellation.
From SpaceWeather.com - "Earth is passing through the debris field of Comet Tempel-Tuttle, parent of the annual Leonid meteor shower. Barring a direct hit by a filament of dust, which forecasters consider unlikely, this year's shower should be mild. Peak rates of 10 to 20 meteors per hour are expected on Nov. 17th and 18th."
More than you ever wanted to know about Leonids here ... from Wikipedia - "Earth moves through the meteoroid stream of particles left from the passages of a comet. The stream comprises solid particles, known as meteoroids, ejected by the comet as its frozen gases evaporate under the heat of the Sun when it is close enough – typically closer than Jupiter's orbit. The Leonids are a fast moving stream which come close to or cross the path of the Earth and impact the Earth at 72 km/s. Leonids in particular are well known for having bright meteors or fireballs which may be 9 mm across and have 85 g of mass and punch into the atmosphere with the kinetic energy of a car hitting at 60 mph. An annual Leonid shower may deposit 12 or 13 tons of particles across the entire planet. Sometimes these trails of meteoroids cause meteor showers and sometimes meteor storms."
Huffington Post also has a nice story about the meteor shower.