Who is Bran Stark from A Clash of Kings and what is their importance?

Bran Stark from A Clash of Kings is the brother of Robb Stark and half brother of Jon Snow. In this novel he is the crippled son of Ned Stark. He was crippled when he was pushed off of a tower at Winterfell because he happened upon Cersei and Jaime Lannister in an intimate moment. He does not remember anything about the day of the fall. There was an attempt on his life in the previous book, supposedly orchestrated by Cersei.

Bran has the ability to get inside another being's body and control it and see through its eyes. In this novel, he's escaped Winterfell while it was burning and with the help of Hodor, Osha, Jojen, Meera and Rickon, he is headed to the North to find the Three Eyed Crow that can explain his abilities to him.