Reddit mentions of Understanding Composition (Expanded Guides - Techniques)

This one is a great little read, very informative without being patronising. Goes into some of the more advanced information as opposed to beginner knowledge. http://www.amazon.co.uk/Understanding-Composition-Expanded-Guides-Taylor/dp/178145051X/ref=sr_1_2?ie=UTF8&qid=1419099021&sr=8-2&keywords=understanding+composition

Lighting an area helps to draw the eye to it, it's a natural response. So, for example, lighting a subject/actor, making them "pop" from the background, will help the viewer's eye focus on that piece of visual space.

In opposition, using shallow depth of field to blur the background will make those details inconsequential.

Empty spaces can also help other regions of the frame became more pronounced. If your shot is mostly dark, for example, except for one area lit by low-key lighting (.e., in a noir film), then the eye will be drawn to that lit area versus the dark one.

There are several YouTube videos where DOPs will walk through how and why they lit a scene, which can be informative.

Composition rules such as rule of thirds are effective because it lends itself to what the human eye naturally finds to be pleasing in a shot. A lot of it has to do with how the shot is balanced, as a decision in aesthetics. Just remember that the visual space is where you can compose semiotics -- signs and meaning making.

I think a book in composition, such as http://www.amazon.co.uk/Understanding-Composition-Expanded-Guides-Taylor/dp/178145051X/ref=sr_1_2?ie=UTF8&qid=1419099021&sr=8-2&keywords=understanding+composition, that shows how visual elements can work together, would be informative for you.