Whether you're trying to impress someone or are tired of only being able to see the Big and Little Dippers when contemplating the night sky, knowing how to find a constellation is a good thing. Cassiopeia is easy to find because it's shaped like a "W" -- or sometimes an "M," depending on its position in the sky -- and you can see it all year long. If you use a telescope, you'll also get the benefits of seeing the nebulae (star dust), star clusters and even galaxies within the constellation. Cassiopeia is high overhead to the north-northeast. First, find the Big Dipper and the Little Dipper. Now, focus in on the point where the handle of the Big Dipper meets its cup. Draw an imaginary line from that point straight through the last star in the handle of the Little Dipper (the star Polaris); that imaginary line will swipe right through Cassiopeia. Its shape should become clear.
Finding Cassiopeia doesn't do much good if you don't know the myth behind the constellation. The Roman myth has multiple variations, but goes something like this: The ancient Ethiopian queen Cassiopeia thought she was more beautiful than all sea nymphs, especially the daughter of Poseidon, god of the sea. To punish her for her arrogance, Poseidon chained Cassiopeia's daughter, Andromeda, to a rock on the coast as an offering to a sea monster. Andromeda was saved, but Cassiopeia was banned to the sky, hanging half of the time with her head downward, signifying her eternal humility.