Seriously, think about the type of light when you're shooting - as Toni and David say. Photography is all about capturing the light - and that is the very simply job that the camera does. However, it is the photographer who looks at the scene and decides it will make a good photograph (or not). Generally speaking, harsh light with huge dynamic range across the image and contrasty shadows is going to look less pleasing to the eye than shooting when the sun is not high in the sky.
I should know: I spent the first 6 months not understanding (or not wanting to believe) this simple point and wondering why my photos often didn't look good.
On the one hand, you want to be taking as many photos as you can to develop your skills, but equally there are times when it will be verging on "wasted effort", frankly. The best piece of advice I could give someone is to stop taking the camera out at midday! I realise that is a bit extreme but, seriously, it is our natural instinct to think, "ooh, lovely blue sky" when the photographer will be thinking, "eurgh, horrible high sun... where's the shade?"
If you are on holiday and want to take holiday snaps then, sure, fire away when you're there... but they will probably look like holiday snaps. Endeavour to get out around sunrise and sunset - tougher in the summer perhaps, but even a few hours after sunrise and before sunset will have far better light than midday. Also go out when the sky is overcast... especially if it has been raining.
However, if you can simply only be there at midday then there are lots of things you can do to rescue an image you want to keep which has been taken in harsh light, but 95% of the time it will look precisely that - rescued. Phil et al have given you some pointers here. Another option is to convert to black & white where high contrast might suit the image better. Ok, blown highlights will still be blown, but it might be more acceptable to your eye.
Hope that helps - please do get out there and take lots of photos but learn from all of our mistakes and focus on getting the right light first and then capturing the right scene after.