Joan Didion, William T. Vollmann and John Updike were among the finalists announced Saturday for the National Book Critics Circle Awards. The fiction nominees included Vollmann’s “Europe Central,” E.L. Doctorow’s “The March” and Mary Gaitskill’s “Veronica.” Two British releases also were nominated: Kazuo Ishiguro’s “Never Let Me Go” and Andrea Levy’s “Small Island.”