Tonight (and early tomorrow morning), a full eclipse will cause the moon to turn red, an event visible for most people in North America.
With the sun behind the Earth, the moon will make its way through Earth's shadow. Which locations will see this lunar event depends on which side of earth is facing the moon when the three celestial bodies line up.
The sky also needs to be clear enough. If the clouds are in the way or you don't have a good seat for the event, you can watch it online with Slooh Space Telescope.
Tonight's eclipse is one of four consecutive full eclipses, known as a tetrad, over the next year and a half. While eclipses occur every six months, there are not usually four full eclipses in a row. All four will be visible for at least some part of the U.S..
Check the map below to see if it's visible from your part of the world. The map was posted by NASA:
"Eclipses During 2014", F. Espenak, Observer's Handbook - 2014, Royal Astronomical Society of Canada
The eclipse will hit each section at the following times (UT=Universal Time): P1 = 04:53:37 UT, U1 = 05:58:19 UT, U2 = 07:06:47 UT, U3 = 08:24:35 UT, U4 = 09:33:04 UT, P4 = 10:37:37 UT.
You can look up the exact timing for your area by using this Eclipse Calculator.