Look into some of the classical composition techniques. Rule of thirds, Golden mean, leading lines, etc... There are endless amounts of books and resources online about this.
http://www.amazon.com …ds=bryan+peterson&x=0&y=0
Go to that link and see the first three books. Understanding exposure, Shutter Speed, and Learning to see creatively. They are great and give really good examples with the settings used and why. Probably some of the best material out there.
Exposure is the first issue for a lot of people. The better the exposure, the lest is needed later, or the easier it is to make something "pop." As for composition, this is just taking more pictures, and actively thinking about this until it becomes second nature. I highly recommend http://www.tmelive.com/
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That used to be the Radiant Vista, but they just redid the site. Fantastic step by step videos and critique about images and their improvement based on color theory, composition, exposure, etc.... I highly recommend it. Hopefully they will get the backlog of Radiant Vista videos back up. They were awesome.