For the beginner, its a moot point. Just set the camera to program and the camera will set the exposure and either utilize it's flash or not. The resulting photographs are hit or miss, usually miss.
Later as you learn more and more, flash and other artificial light sources are introduced to make a technically good photographs. A great blog to learn about using small strobes is the Strobist.
The trap in using artificial light sources is that it provides an easy solution but you tend to use it as a crutch and overlook the great available light.
Standard operating procedure for covering red carpet events in Hollywood is to use flash on a bracket. It provides even, shadow free lighting that most magazines like. The problem is that all the photographs look the same, which is good for the magazines as it provides a consistent look on a page.
I try to have one camera with flash and one I use for available light. I can usually shoot all the photos with one camera with a flash and 24-105mm lens. The second camera has a 70-200mm lens for available light shots.
Last Sunday's Grammy Awards was a perfect situation for shooting available light. Because of the threat of rain, the red carpet area was tented which blocked out any exterior light, making the lights they set up very consistent. If the event was held outdoors in bright sun, it would be a challenge to balance flash to fill in harsh shadows cast by the sun. And that sun would be constantly changing in exposure and color temperature as it got closer to sundown.
The one thing to consider when shooting available light is not only the exposure, but the color temperature or white balance. Most modern digital cameras have a few standard settings like sun, shadow, flash, fluorescent, tungsten (it's symbol is a light bulb) and auto white balance. People who shoot video really key on the white balance as they know if they screw that up the video will be unusable.
For still cameras, white balance range from bluish-ness of daylight to orangey-ness of tungsten to green cast of fluorescent. You can manually put a Kelvin number in your digital camera to match the available light. Most of the time Auto White Balance works, but with some cameras, like my Canon's, shooting in tungsten lighting will give you poor results.
At the Grammy's they had the ideal lights, which were daylight-balanced movie lights. They were mounted very high on light stands which gave even, shadow free lighting. They were also really bright, I shot at ASA 400 at 1/500th at f2.8. The beauty of shooting available light is that I can shoot at f2.8 and blur out the distracting background. I also didn't have to worry about my flash recycling.