Clark was born in 1948 on the Lower East Side of New York City and raised on Long Island, where he attended Catholic schools. He graduated from Providence College in Rhode Island with a degree in English and earned a Ph.D. from the State University of New York at Stony Brook. In 1977 Clark was hired by the St. Petersburg Times to become one of America's first writing coaches. He worked with the American Society of Newspaper Editors to improve newspaper writing nationwide. Because of his work with ASNE, Clark was elected as a distinguished service member, a rare honor for a journalist who has never edited a newspaper. Clark is the author or editor of 14 books on journalism and writing.