He has contributed to (and often been sole author and editor of) some 150 reference books, mostly in the areas of the arts, language, local history and popular interest.
Pickering was a pupil at Dryden House, Oundle School.
He graduated in English from St Peter's College, Oxford.
[1] Dictionary of the Theatre, edited by Pickering and published by Sphere in 1988, is intended to be a comprehensive dictionary of important plays and figures in the history of theatre.
Derek Paget, writing in New Theatre Quarterly in 1990, wrote that the Dictionary was "likely to be of great use as reference (and as a first line of inquiry) to a wide range of people".