Take lots of pictures, analyse the results, learn from your mistakes. If you don't like what you see in your picture ask yourself what the problem is and try again.
As was mentioned take notes on exposures used. Photographs are everywhere; study them, observe where the light source was and how the photographer exploited it for maximum potential.
Above all, take lots of pictures and turn off your program/auto-everything modes and use the camera in manual, setting aperture and shutter speed yourself.
Above all have fun and don't turn your photography into a technical treatise, 99% of which you don't need to know.
'Making the simple complicated is commonplace; making the complicated simple, awesomly simple, that's creativity'
Charles Mingus