Final answer:
When entering a roundabout, yield to vehicles already circulating within it and move counter-clockwise or clockwise depending on local driving norms, always prioritizing vehicles in the roundabout.
Step-by-step explanation:
When entering a roundabout, you must yield the right of way to the traffic already in the circle and move in a counter-clockwise direction in countries where you drive on the right-hand side of the road, such as the United States, or clockwise in countries where you drive on the left, like the United Kingdom. You should look to your left and gauge the flow of traffic before entering. Vehicles in the roundabout have the priority, and those entering must wait for a safe gap. It's important not only for legal reasons but also for traffic flow and safety to adhere to these rules. Once you have entered the roundabout, you should maintain a steady speed and follow the circle until you reach your desired exit.