I am still learning what works and doesn't work for me in terms of style. And I have found that one of best ways to develop one's own sense of style is to draw upon the inspirations of others.
Image based blogs like Sea of Shoes, the Sartorialist, Jak and Jil, and JJJJound are a great way to get started and create a portfolio of images that inspire you. But, it is also important to think about what ideas created these distinctive senses of style and how you can use the images that inspire you and translate them into your own wardrobe.
That is why I like looking at sites like http://bonvivantconsulting.com, where the focus is on honing in on how to create one's own style and the wardrobe to go along with it. It took me a long time to think about my clothes in terms of a wardrobe rather than individual pieces. And it's blogs like bonvivant that can help develop that holistic sense of one's closet.