Believe it or not, but Cassiopeia is a lady sitting in a chair. Actually she's usually refered to as the Queen, since she was a queen in ancient mythology. Most people recognize it as just the "W" or "M" in the sky. It is located on the opposite side of Polaris from the Big Dipper - so if you can find the Big Dipper in the sky, you need to look towards the opposite side of Polaris to find Cassiopeia. Sometimes the Dipper or Cassiopeia are not easy to see since they can be located very close to the horizon.
Like Ursa Major, Cassiopeia is circumpolar - we can see her most any time during the year, however she is easiest to see during the late summer to early spring months when she is highest above the horizon.