Lunar Eclipses can only occur on the Full Moon when the Sun and the Moon are in the aspect of opposition. The Earth is between the Sun and the Moon and the Moon is passing through the Earth's shadow.
The New and Full Moons occur every month but eclipses far less frequently. A Lunar Eclipse can only take place when a Full Moon occurs near the Lunar Nodes. A Lunar Eclipse always occurs at the opposite Node at which the Solar Eclipse in the same sequence occurs. There are usually two Lunar Eclipses in a year about six months apart one another, but sometimes there can be even five Lunar Eclipses in a year, although this is very rare.
Lunar Eclipses are visible at the same time from all locations where the Moon has risen above horizon.
There are three kinds of Lunar Eclipses: Total, Partial and Penumbral.
NASA - Lunar Eclipse Page
NASA - Eclipses and the Saros
NASA - Lunar Eclipses of Saros Series 1 to 175
Sphinx Lunar Eclipse charts:
14.03.2006 in Virgo - Penumbral
07.09.2006 in Pisces - Partial
03.03.2007 in Virgo - Total
28.08.2007 in Pisces - Total
21.02.2008 in Virgo - Total
16.08.2008 in Aquarius - Partial
09.02.2009 in Leo - Penumbral