Light is everything in photography, in fact it's even part of the meaning of the actual word from its Greek roots:
Photography – drawing with light
In learning to see light I often recommend that you try shooting in black and white mode on your camera for a while. It limits what you see to tones and light and dark only. Taking away the color and all the other distracting elements can be helpful in learning about light. Try it!
Here are some great black and white photos I found that make fabulous use of light. Enjoy!
Note: these are not my images and are shared here from the 500px site using the 500px license. So get more information about any of the images just click them to go to the original where you can comment directly to that photographer.