Selene was the Goddess of the Moon. She was the daughter of the two Titans Hyperion and Theia (see below). She married mortal Endymion (a shepherd who she caused to sleep forever so that he wouldn't get old and gross) and had 50 daughters (I don't know what happened to them). If you want to read the longer version of the story, read it here. She is a part of the Triple Goddess (there will be a section on the Myth pages explaining the phenomenon of Triple Goddesses, so keep looking). She rode across heaven in a chariot with milk-white horses. In Roman (puh-tooey) mythology she was called Luna.
A Goddess of Temperance and Moderation. This concept seems to be pretty important to the Greeks, although I can no longer find my source for this goddess, and she was clearly not that crucial a deity.