The main technical challenge when photographing from an aircraft is overcoming vibration. Set short shutter times to minimize camera shake caused by the plane and use image stabilization lenses if possible.
Normal to telephoto lenses generally give the best results. Another common problem is finding a clean window to shoot through. When flying in a propeller-driven aircraft, remember you may not be able to see the propeller, but it can easily be caught in the picture.
Adapted from Fundamentals of Photography by Tom Ang (Alfred A. Knopf, 2008; $25)