[PhotoNewt]

As Inkista correctly pointed out you need a longer lens. I have been able to get decent shots from a 200-300 mm lens but the best are in the 400-600 mm range.

When metering the moon with these long lenses, fill the viewfinder with the moon and overexpose by 1-2 stops to keep the moon white rather than grayish. Use a manual exposure mode to set the value once.

Regarding exposure, I usually set my lens at f/8 (depending on the lens) and increase the shutter speed as much as possible (ISO around 400 sometimes to get a faster shutter speed). The best shots are obtained when the moon is low on the horizon, if you close your lens too much and use a slow speed, the movement of the moon will keep you from getting a sharp image.

Always use a tripod for this. Also use a a remote shutter release or the self-timer function along with mirror lock to reduce camera shake as much as possible - with lenses in the 300-600 mm range, camera shake is greatly magnified and can ruin a shot in a hurry.

Hope this helps.