About 100 feet.
When you are making a turn, when you are changing lanes, or when you are pulling away from the curb or are parallel parking. Activate turn signals 200' before making a turn.
100 ft
When turning you should signal during the last 100 feet before a stop sign. This is courteous to all drivers around you.
100ft
100 feet
100 yards
Lift the stick to the right of the steering wheel up to activate the right turn signal and down to activate the left turn signal
100 ft ahead
100 feet
100 feet
At least 500 feet.
Almost every car nowadays come with a turning signal. If you do not have a turning signal, a legal way to signal that you are going to turn would be to stretch out your hand in the direction that you are turning to. Otherwise, you can install two lights (flashing or not) on the two corners of your car. Link it to the buttons near the driver's seat for convenience, and press the button to activate the lights as a signal.