Working with Available Light
Available light is in many ways the most convenient way to photograph. It requires the least equipment, but it also requires the keenest observational skills and, as a result is one of the most rewarding. It gives you an excuse to go and appreciate the everyday subtleties of light in your surroundings. The other great thing about working with available light is it is the least intrusive. You don't have flashes going off, banks of lights or reflecting boards.
I hope if you are reading this section you instinctively know where the sun is, and ensure that the subject has the best possible light to suit you desired result. This doesn't mean you aren't photographing during the middle of the day, but you are very aware of the bright light, strong shadows and washed-out colours.
Remember, you can increase contrast and colour saturation by using a polarizing filter in some situations. Note that a polarizer is not a good all purpose filter and does not in any way replace a UV or Skylight filter on your SLR.
I strongly recommend looking at other photographer's work and try and figure out where the sun is, have they used any other lights or reflectors? If there is a person you may be able to see the reflection in their eyes of a flash. The Links Section has links to some of my favourite sites and books.