Here's some tips.

Shutter speed: A general rule of thumb for sharp pictures is that your shutter speed should equal the focal length of the lens you are using. ie using a lens of 100 mm your shutter speed should be at least 1/100s. When using a support (tripod etc) this negates this "rule". Now when you want to get artsy, you can play with shutter speeds to give specific effects (blur for example)


ISO = essentially the sensitivity of the sensor to light which sort of equats to film speed. This has an effect on shutter speeds. Be careful with using high iso settings because it can induce noise/grain into your picture. However, this is not a bad thing in the cases of artistic photography. Can be adjusted to compensate for low shutter speeds.

Aperture or f stop: this is an interesting one which takes some time to get used to. It is the diameter of the lens opening. f/2.8 is a larger opening than f/11 which allows more light to enter the lens. However the photo taken at f/2.8 will look alot different than that taken at f/11. Google hyperfocal distance for more in depth discussion on this.

My camera is set to aperture priority in probably 95% of the photos I take. Essentially you can isolate the subject from the background using a large (f/2.8) aperture setting whereas a f/11 aperture setting will have more the background in focus. The plane of focus is different.

cheers.