His book titled "Audacity of Hope" clearly delineates his belief. The book was published in 2006, long before his presidential campaign. He wrote the book himself with poetric languange.
Another book, "The Dreams of my father" was written in 1995, when he was a junior senator of the State of Illinois. It provides a unique insight into his aspiration and personal journey.
He has turned a new page in US history, not because of him become the first African American president and his rhetoric, but more because of his vision and his domestic/foreign policy which will essentially rejuvenate US.