My first piece of advice is to move away from the auto button! I know, I know it's pretty easy to switch to that and let it do all the work, but trust me, cameras can be lazy little things when they want and if you want to improve your photos you need to put a little hard work in!
First off you need to know your camera, get that manual out and start reading! You also need to understand light, as essentially photography is all about drawing with and controlling light.
Theres 3 things you can do to manage the light. Aperture, shutter speed and ISO.
Aperture is the 'F' stop on your camera. The higher the number eg F16 the less light your camera will allow in, the lower the number ie 2.8 the more light can actually pass through the lens (as the diaphragm is open more).
Shutter speed is pretty much as it reads - How long the shutter stays open for! This is measured in seconds so when your camera displays 1/200 that means the shutter is open one two hundredth of a second. If your camera display reads 0.4 this means your shutter will stay open for 0.4 of a second (which is a LOT longer than you think in shutter speed terms!). I would always recommend sticking to the general rule of never going lower than 1/60 as you will start to see blurry photos appearing! If you're wanting to capture action then I suggest shooting at around 1/500th of a second.
And lastly ISO, in essence this is how sensitive your image sensor is to light (its traditionally used to grade how sensitive a film was to the light). The higher your ISO, eg 800 the more sensitive to light it will be, the lower the number eg 100 the less. So if you're in a field on a bright sunny day then 100 is the way to go, however if you're in an indoor hall with only a small amount of light you're gonna be looking at getting that number pretty high. The only issue you will find is the higher the number the more grainy your images can look. ISO is probably the hardest of the 3 to understand as a newbie but once you nail it and get the combination of the 3 there'll be no stopping you!
As this is a pretty long post and requires some taking in I'm gonna leave it at that for now. If you really want to get your head around it though you need to practice, practice and practice some more! Set up an object on your desk and get used to how altering these settings can make an impact.
Try putting your Aperture at f5.6, your shutter speed at 1/125 and your ISO at 400 and take a photo.
Now keep those setting and change your ISO to 800... Can you see the difference?
Now put your iso back to 400 and change your shutter speed to 1/500.
The more you play around with changing each of these and seeing the difference it makes the more you will understand the light. Also keep an eye out for the exposure indicator on your screen, if you get that on the 0 all being good you should have a pretty good exposed image!
I hope this helps at least 1 person. Please leave comments of any questions you have and I'll try answer them! Also some questions for future blog posts would be ace!