In semi automatic mode:
-Shutter Speed (time shutter is open):
long shutter speeds (small number), means crisp moving objects (ie flowing water, running, moving things look still).

short shutter speeds (large numbers), means blurred moving things (water flowing, cars smearing by, etc).
Why does a big number mean faster? The number listed is the denominator of a fraction–1/60 of a second.

http://en.wikipedia.org/wiki/Exposure_(photography)

-Aperture (opening size):
Small opening (large number an ‘fstop’) means things are in focus far away and up close, there is a deep depth of field.
Large opening (small number) means things are in focus in a very precise distance. Shallow depth of field.

To make it seem intuitive that the bigger number means a smaller opening I think of the fstop as a fraction 1/number. for details on that fraction see: http://en.wikipedia.org/wiki/F-number

http://en.wikipedia.org/wiki/Depth_of_field

Film sensitivity: ISO setting of the ‘film’
This give more or less light sensitivity. The trade off is: the more light sensitive the film is (higher number), the more grainy the image is.
Smaller numbers (100) less light sensitive but very crisp images (highest resolution for the camera). Best for daytime outdoors or well lit areas.
Larger numbers (3200) means very light sensitive. Great for night shots (parties, concerts, etc) colors appear more saturated too it seems.

———
Other thoughts I have while shooting

Handheld what’s the slowest shutter speed you can use without the image stuttering/smearing/blurring?

60 (1/60th of a second) is my rule of thumb but I will push it to 50 for a lens that is very far away from everything (a wide angle lens).

Framing the photo:
art

What is photo’d:
art

Which settings used:
art

I tend to use Aperture Priority and Shutter Priority modes when shooting. I ‘focus’ on depth of field in AP mode and motion of object with SP.
I turn my ISO up enough for low lighting conditions when a tripod is not possible.

I suppose the next level of my technical skills is putting things in fully manual mode.
Adjusting aperture and shutter speed manually, keeping in mind motion and depth of field.

I almost forgot Exposure compensation. In one of the semi-auto modes it can be useful to brighten up and image or darken if the automatically calculated exposure isn’t seeing the image as you do.