The Twilight setting (a little moon shows up on the LCD screen)... use that for night shots to try to pick up any light that may be in the area. Picks up some light... if it is bright enough.

SHARPNESS - The Aperture controls how much light is passed through the lens... you set this... say a butterfly is sitting on some flowers... and you want everything in that photo to be sharp... you would set this to a high number. If you want only the butterfly to be sharp, you would set this to a lower number.

Looking through the LCD Screen
    

Photos using the Aperture Setting
    

MOVEMENT - The Shutter Speed determines HOW LONG the shutter stays open... you set this when you want to capture something that is moving. To catch a hummingbird's wings (which move very fast) to stop it in motion... set this to at least 1500. If you have enough natural light, set it up higher!