Finding the Pole Star
The Plough points to Polaris in Ursa Minor (in North America the Plough is the Big Dipper)
Following the line from the 2 end stars of the Plough, the next bright star is Polaris, the Pole Star.
Polaris is not exactly at the pole (the point in the sky pointed to by the Earth's axis) but about 1 degree away from it. Also it will not always be the pole star. The Earth's axis slowly wobbles (with a cycle of about 19,000 years) so that for long periods there is no star near the pole. It was fortunate for early trans-oceanic explorers that they had Polaris to help them navigate.
The Greeks called the star Kunosoura, meaning dog's tail. What we call Ursa Minor (the constellation of the little bear) they must have thought of as a dog. But because medieval navigators used the star as a guiding light, we get the word "cynosure" from this.