The new season of Game of Thrones starts April 1, 2012.
The second season of Game of Thrones follows George R. R. Martin's A Clash of Kings, which is the second book in the A Song of Ice and Fire.
The book's description from Wikipedia is as followed: A Clash of Kings picks up where A Game of Thrones ended. The Seven Kingdoms of Westeros are plagued by civil war, while the Night's Watch mounts a reconnaissance force north of the Wall to investigate the mysterious people, known as wildlings, who live there. Meanwhile, in the distant east, Daenerys Targaryen continues her quest to return to and conquer the Seven Kingdoms. All signs are foreshadowing the terrible disaster that is to come.
The new season starts April 1, 2012