Five stars in a zigzag, 15° end to end: Cassiopeia. It reads as a W or an M depending on which side of the pole it is currently on, which is disorienting the first few times and then becomes a clock. Four of the five are brighter than magnitude 2.7, so it survives a bad sky.
Schedar (α Cas, 2.24) and Caph (β Cas, 2.28) are 4.9° apart at one end; Cih (γ Cas, nominally 2.15) sits 4.7° the other side of Schedar. Cih is the interesting one: a shell star spinning near break-up, which has flared as bright as magnitude 1.6 and faded to 3.0 within living memory. If the W ever looks lopsided to you, it probably is.
The W is two V's back to back, and the deeper one — Caph down to Schedar, back up to Cih — opens toward the pole. Bisect that V and run the bisector out 32.8°, about five times the V's own width, and you land on Polaris. The common mistake is to shoot Caph straight through Schedar instead; that line misses the pole by 26°.
Here is why you want two pointers. Cassiopeia and the Big Dipper sit on opposite sides of Polaris, each roughly 30° out, so they see-saw: Schedar is near the zenith right now and Dubhe is down at the altitude on the readout, wading through the thickest, murkiest air in your sky. Six hours from now they will have swapped. One of the two is always usable.
Twelve hours, half a turn. Cassiopeia swings right around the pole without touching the horizon — the altitude readout never approaches zero — and the W rolls over into an M on the way. Anything north of declination 90° minus your latitude does this; Cassiopeia's five stars run from +56° to +64°, which puts the whole W inside that circle from anywhere north of about 34°N.
Cassiopeia is lying across the Perseus arm of the galaxy, one spiral arm outward from ours, which is why the field behind it is so crowded. Follow Cih and Ruchbah south-east and you reach the pair of open clusters known as the Double Cluster — NGC 869 and NGC 884, magnitude 3.8 each, half a degree apart. Under a dark sky it is a naked-eye smudge; in binoculars it is two hundred hot young stars and one of the finest sights in the northern sky.