The former Vermont governor, currently regarded as the liberal Democrats' best chance for a shot at the presidency, has signed with Simon & Schuster to do a book for publication in November. Geoff Kloske will edit it for trade paperback, and it was acquired by publisher David Rosenthal from agent Bob Barnett at Williams & Connolly, the politicos' book agent of choice. Dean, who has won a large following among student antiwar activists in particular, will talk about his life, his governorship, his political views and his prescriptions for the country in such areas as health care, social justice, education and the environment.