Photographic Rules of Thumb
Image resolution needed: 300 dpi for printing, 72 dpi for computer screen
Handholding the camera: most people can handhold no slower than 1/60th second. Some can go down to 1/30th. Safest is 1/125th or above. (If the shutter speed is too slow, camerashake will make the picture blurry.)
ISO: for point and shoots, 200 or 400 are OK. Anything faster (larger #s) depends on the camera; you get what you pay for.
Rule of thirds: composition is more attractive if key elements are not centered, but 1/3 of the way from an edge.
When there are people in the picture, focus on their eyes. That’s the part of the picture that people most care about.
When there are people in the picture, expose for their faces. Ditto.
Size of image: despite the current discussion about how megapixels don’t matter, that’s only when you get to large numbers. Larger image files = more pixels = you can crop and still have a good image.
Never ever ever use digital zoom, only optical. Digital zoom just makes the pixels bigger. (Most p&s cameras will do optical zoom up to a point, then zoom further with digital. Turn off the digital.)