If you're driving slowly, the best lane for you to drive in is the far right lane, if there is more than one lane going in the same direction as you.

When traveling on a freeway or highway, your car should stay in the right lane, unless you're passing another vehicle. There are often signs to remind you of this. However, be aware that on interstate highways, the right lane within an urban area is sometimes only for exiting the interstate at the next opportunity.

If you're at an intersection, American drivers usually defer to the vehicle which arrived at the intersection first. If two vehicles get there at the same time, the driver on the right proceeds, unless stopped by a red STOP or YIELD sign.

Don't honk your horn, unless you're in a situation where you need to get the attention of another driver or pedestrian. For example, it's OK to honk when another car is about to hit you, but you may find that honking in the US is less common than in other nations.

The speed limit in residential areas is often 35 miles per hour (60kph), but is as low as 25 or 30 miles per hour in many areas. On interstate highways and roads with very little traffic and intersections, the speed limit is commonly 55 miles per hour or higher.

Source: Vroomvroomvroom.com