Hi Janet_P, I?m new here, and this is a great topic to start with, as I?m a pilot and had an aerial photo business on the East Coast.
Any camera will work, but I think the nicest photos are those taken at low altitude, around 500 to 1000 feet above ground, with a wide angle to normal lens. This shows detail in objects close to the aircraft and also gives a nice distance perspective. I used 28-35mm lenses on a 35mm Nikon and 55-75mm lenses on a Pentax 67. A wider lens will image part of the wing or landing gear, and a longer lens will be more likely to show vibration or blur. Use the highest shutter speed possible, as the lens aperture can be wide open.
Like someone mentioned, the best aircraft is a Cessna 172 or similar, with a window that can be opened fully. Shooting through a plastic window is never as good as an open window. The window of most Cessnas will open wide enough to shoot through, and if you are inclined, you can easily remove the screw from the window support brace, which allows the window to open flat against the wing in flight. Just remember to reinstall the screw after landing. Low wing airplanes are more difficult to use, but still most have a small vent window that opens, allowing a clear area to shoot through.
Whatever airplane, keep the camera strap around your neck, and the camera inside so that the airflow rushing by outside does not vibrate the camera. And finally, an airplane with an open window is very LOUD, so if possible wear a headset, allowing communication with the pilot in flight.
Good luck, and enjoy!