I use a Canon EAS 20d with a variety of lenses.
i find the best lenses for aerial shots are either a 24mm or 50 mm fixed focal lenght wide angle lense. Reason being wide angle lenses are better for landscape shots.
A few thing to remember when taking aerial shots:
1) The greater the F stop (apeture setting) the wider the focal spread
2) The faster the ISO speed the less bluring of the image (but it may be more grainy)
3) The faster the shutter speed the sharper the image.