Read
Most writers love to read. The written word becomes spellbinding. Besides doing it for pleasure, reading will improve your writing. Take note of author’s styles, use of language, dialog and description. Notice the movement of the characters throughout the story.
Author Maggie Stiefvater recommends to aspiring authors to read, read, read. She did not take any creative writing classes, but she is a voracious reader (as told in a Borders interview). Reading is like studying about writing, while enjoying a good story. It is good to read various genres, to get a good idea of what works for your style.
So, next time you pick up a book, think of its benefits to you as a writer, besides being pure entertainment.
Inkspeare 
I firmly believe in read to write. We are what we eat? I believe we write what we read (so we do need to show some discretion in our reading). The thing is, though, for me I have to trust my unconscious mind to do the learning. The stories where I look at style, language, dialogue and all are not the ones I want to learn from. Rather, it is the stories where I am so absorbed I forget to look — those are the ones I want.
-Michael
I agree, usually it takes a second read to focus on the style… on the first read you just want to devour the book. I like to read several genres; I always learn something different.