Politically anarchist, Leier's books have mostly reflected on British Columbia's rich history of labour radicalism. His first book, Where the Fraser River Flows: The Industrial Workers of the World in British Columbia (1990) deals with the famous syndicalist, working class rebels, while his second, Red Flags and Red Tape: The Making of a Labour Bureaucracy (University of Toronto Press) deals with the institutionalization of a non-revolutionary labour movement. In Rebel Life: The Life and Times of Robert Gosden, Revolutionary, Mystic, Labour Spy (1999), Leier examines the life of an Industrial Workers of the World member (or "Wobbly") turned police labour spy. His fourth book, Bakunin: The Creative Passion is a biography and political chronicle of the 19th century Russian anarchist, Mikhail Bakunin and is being published in paperback by Seven Stories Press.
As part of the Graphic History Collective, he helped produce May Day: A Graphic History of Protest," available through the SFU History Department.
A former folk singer, Leier is also known for bringing a banjo to his history classes.
- Where the Fraser River Flows: The Industrial Workers of the World in British Columbia. Vancouver: New Star, 1990.
- Red Flags and Red Tape: The Making of a Labour Bureaucracy. Toronto: University of Toronto Press, 1995.
- Rebel Life: The Life and Times of Robert Gosden. Vancouver: New Star, 1999. Rev. Ed., 2013.
- Bakunin: The Creative Passion. New York: Seven Stories Press, 2009.
- http://catalog.sevenstories.com/products/bakunin Seven Stories Press