For the settings, here's a guide that you may want to follow:
- Set the Metering mode to "Spot metering". Setting's location varies in every manufacturer or sometimes even models of the same make so it would be best to dust off the owner's manual that came with the camera to look where it is located. In Canon, mostly if you press Menu key, you should be able to see the metering option in there.
- Set the camera mode to Manual. If your camera doesn't have a manual setting, you can still try using auto mode but I'm pretty sure it's not going to look good.
- Set the aperture (f) to around f8.
- Set shutter speed to 1/25sec.
- Set ISO to the lowest. It's usually 100 for Canon and 200 for Nikon.
- Put the camera to a tripod or something sturdy and fully zoom in to the moon