Are you into digital photography or film? Probably a silly question these days. I guess there are a fair few facets to it and it probably makes sense to focus (no pun intended) on one part at a time.
Broadly speaking it boils down to the artistic side - planning shots, composing them, deciding what you are after and how you want it to look and the techincal side - understanding how the camera works and how to configure it to take the shot you want, and, increasingly these days, that extends into post-processing of the image (although a surprising amount of that could be done in the darkroom too).
There is a bit of crossover too - lighting can fall into both areas, for example.
Some of this can be learnt easily, some of it is more instinctive and it you're not artistic in the first place that side can be pure trial and error, and very difficult to move forwards (from personal experience).
An evening course or going along to a camera club might be a good way to make progress - it will give you assignments so you have ideas about what to go and take pictures of, instead of just ambling around looking for inspiration.
Can't specifically recommend any books as most of mine are from the days of film, and I guess that's not what you're after - although 90% of the theory is identical.
Kevin