Blood Moon: Diagrams explain how eclipses work. Space.com has a big page of more information about blood moons, lunar tetrads (NASA video), a calendar of the four lunar eclipses 2014-15, and a great downloadable infographic called Shadow on the Moon that sums all this up in graphic form! Most of this will be valid for the next three eclipses as well! Going in Astronomy.
Lunar eclipse: When the moon passes through the Earth's shadow, it causes the moon to look very unusual for a short period of time. This event is called a lunar eclipse, and it occurs roughly twice a year.