Using the built in light meter in your camera
By far the most powerful feature of any camera is that little meter that shows up at the bottom or the side of your viewfinder when you look through your camera. The reason this is the best feature is because it will instantly tell you if your image is going to turn out before you even activate the shutter.
Make sure your camera is on Manual mode, then look through the camera at something you want to photograph. Is the meter reading 0 (zero) or is it off the scale in one direction or the other? If it's between 1 and -1 then your exposure is pretty close and depending on how much of your composition is bright or dark you may be spot on even though your meter is not reading 0.
This is where your Manual mode will become your favorite setting because as long as you keep the meter close to zero your image will be pretty well exposed! Not only that but it will become second nature to you to spin the shutter dial (or apeture dial) to correct your meter reading as you are shooting.
This is the best tool in your photography tool box and the more comfortable you get with it the better your photos will be. You will learn to adjust for overcast skys and dark clothing where your auto setting would average the metering and cause more work for you in Photoshop after the shoot is over.
So go grab your camera and start to learn how to use that light meter and your camera's manual mode!