Good advice so far for the most part.
However, number one most important thing for you is to understand ISO, Shutter Speed, and Aperture.
And guess what, you don't need to buy a book
as others have suggested. Save your money, all the info you need is free online.
Here is a brief summary:
- ISO - higher number means more light and more grainy photos, lower number means less light and less grainy. Basically shoot ISO 100 when you can unless you are trying for an artistic grainy look.
- Shutter Speed - Determines how long the sensor will absorb light. The longer it is open, the more light it gets. High numbers mean shorter time the shutter is open (less light), low numbers mean longer time (more light).
- Aperture - this one is somewhat confusing. I recommend reading the wiki page explaining how the aperture number is determined. It is the relationship between the width of the opening in your glass and the focal length of the glass. Sound confusing? Then just pay attention to this:: bigger number means less light and more stuff in focus, small number means more light and narrow focus (dof, or depth of field).
Those are the three tools your camera
uses to determine proper exposure.
The other determining factor - light.
You will want to google up to learn about a stop of light.
1 stop of light
is just a standard measurement like an inch or gallon, but it is measured by exposure.
To understand more about lighting photos check out strobist.com.
Doubling shutter speed from 400 to 800 will make your photo 1 stop darker,
halving from 400 to 200 will make it 1 stop lighter. The double/half relationship
works for aperture and ISO as well.
Use the right hand of the page to go through David Hobby's lighting tutorials. He will also give you some insight into photo composition, which you seem to struggle with a little. Basically the guy is the bees knees.
Again, as you get more into this you will learn there is more too it, but focus on he relationship between those three in camera elements for now--then learn how to use light to get the photo to look the way you want.Edited by mrwesth - 6/11/11 at 5:40pm