One very useful tool is histograms. It is a graph that gives an average reading based on
exposure in your shots.
If you do a little research in them and learn how to display it on your camera and read them, you will find it much easier.
They can tell you if your shot it overexposed, underexposed or just right. This is more of an advanced aspect of photography but very useful.
Another handy tip, if you are shooting at say 50mm, keep your
shutter speed at 1/50 or quicker (1/80...1/100 etc etc). This will help you take a picture that is not blury and in focus. If you find that there is not enough
light to expose the image at 1/50, you can then do other things to compensate. Like adjusting
aperture to let more
light in (2.8 is larger than 5.6, this is hard to understand sometimes, but remember....smaller number means bigger hole which means more
light).
You can also adjust
iso to allow the shot to expose correctly.
If you can answer please answer these things, it will assist myself and other to help you:
What modes do you find yourself shooting in? Full auto (A), programmed auto (P),
Aperture Priority (Av),
Shutter priority (Tv) or Manual (M)?
What do you understand so far about the technical side of photography?
What are you biggest problem? Images too dark, to
light, not in focus?
And what is your current kit made up of? (camera,
lens' etc)
Cheers
T.S.