If you’re looking for beginner’s books on American labor history/politics, I’d recommend Nelson Lichtenstein’s State of the Union, Phillip Dray’s There Is Power in a Union, my colleague Erik Loomis’ A History of America in Ten Strikes. Thomas Geoghegan’s What Side Are You On, and Kahlenberg and Marvit’s Why Labor Organizing Should Be A Civil Right.
If you’re looking for beginner’s books on more global stuff, I’d recommend E.P Thompson’s Making of the English Working Class, Sassoon’s Hundred Years of Socialism, Jefferson Cowie’s Capital Moves, Leon Fink’s Workers Across America, and my colleague Erik Loomis’ Out of Sight.