what are the rules for which lights to turn on, and when?
Most airlines will have nav lights on all the time, but legally it's at sundown or when it begins to get dark. Strobes are from runway to runway, just not at the gate or taxi ways. Landing lights for big airliners must be on below 10,000 MSL. In smaller planes you can turn them off once you are about 10-20 mi away from the airport. It usually depends on the plane.
Navigation lights whenever you're in the aircraft with the power on. Landing lights for landing and take-off, and usually below 10,000 feet for added visibility at night. Turn them on when entering the runway or descending below 10,000 feet; turn them off when exiting the runway or climbing through 10,000 feet. Strobe lights on upon entering the runway; off after landing and exiting the runway. In heavy fog, turn them off so that you aren't blinded by the flashes (but not all versions of Microsoft Flight Simulator simulate this—from your questions I gather that you're probably simming).
Nav Lights : On between official night and official day Strobe lights : On just before take off until landing Landing Lights : not a strict rule, but usually on before take off up to 10,000 ft and then off for cruise and on again below 10,000 ft until after landing, however it is requires by law to have operational landing lights if you carry passengers at night.
FAR 91.209 states that position lights (nav lights) must be used from sunset to sunrise. It also states that if anticollision lights (strobe and/or beacon) are installed, they must be turned on at all times when operating the airplane unless it is safer to operate without them, such as near other airplanes during ground operations or while flying through clouds. Advisory Circulars AC 91-73A and AC 120-74A have recommendations, but they aren't rules. The recommendations are to use the rotating beacon whenever the engine is running. Turn on nav and strobe lights prior to starting the taxi. Use taxi lights while moving, and turn them off when stopped. Turn on all available lights when crossing a runway. Turn on all lights except for landing lights when cleared onto the runway (position and hold). Turn on landing lights when cleared for takeoff. The AC does not specify when to turn off the landing light after takeoff or when to turn it on before landing. Common sense says keep them on when in high traffic areas. In jets, we normally keep the landing lights or recog lights on whenever we are below 18,000 feet. Obviously, this doesn't apply to small propeller planes. When I was instructing in Cessnas, I would keep the landing lights on within 10 miles of an airport when entering or leaving the traffic pattern and while in maneuvering flight when I wanted to be more visible.
