The typical route to the top of the New York Times best-seller list takes an author to swank Manhattan publishing luncheons and the morning talk-show circuit. But radio and TV host Tavis Smiley, editor of The Covenant with Black America--a manifesto by prominent African-Americans, including former Surgeon General David Satcher and Princeton professor Cornel West, that will reach No. 1 on next week's nonfiction paperback list--just went to church. Published in February by the small black-owned Third World Press, the Covenant has sold 250,000 copies, many on Smiley's barnstorming tour of African-American congregations around the U.S. Each revival-like meeting has drawn hundreds--in some cities, thousands--with many in the audience buying armloads of books to give to friends and relatives. The book is a nonpartisan agenda for black progress. Its prescriptions range from the individual-- "Invest in a home computer"--to the societal--"Strengthen the Voting Rights Act." The Covenant's success may have surprised the publishing world but not Smiley, who says, "There is a hunger and a thirst on the part of black people for leadership--a blueprint, a game plan, a guidebook, for how to make black America better."