If you can watch only one, watch this collection of classic labor movement films:

http://www.amazon.com/Classic-Labor-Unions-Films-DVD/dp/B000O27OVC/ref=sr_1_10?s=movies-tv&ie=UTF8&qid=1374941444&sr=1-10&keywords=labor+movement+documentary

Other documentaries worth watching:

Chicano!  Struggle in the Fields–see Available Online tab

At the River I Stand–see Available Online tab

http://www.amazon.com/Take-Naomi-Klein/dp/B000CCD1X4/ref=sr_1_2?s=movies-tv&ie=UTF8&qid=1374897840&sr=1-2&keywords=the+take

http://www.amazon.com/Harlan-County-U-S-Criterion-Collection/dp/B000E5LEVU/ref=sr_1_1?s=movies-tv&ie=UTF8&qid=1374941285&sr=1-1&keywords=harlan+county

Hard to find:

http://www.filmandhistory.org/documentary/labor/inheritance.php

http://www.amazon.com/No-Grapes-Pesticide-Exposure-Documentary/dp/B000MCXTX6/ref=sr_1_1?s=movies-tv&ie=UTF8&qid=1374941561&sr=1-1&keywords=no+grapes

http://www.asianwomenunited.org/labor-women-2002/

Fictionalized accounts:

http://www.amazon.com/Norma-Rae-Sally-Field/dp/B000059HAN/ref=sr_1_1?s=movies-tv&ie=UTF8&qid=1374941355&sr=1-1&keywords=norma+rae

http://www.amazon.com/Harlan-County-War-Holly-Hunter/dp/B00005KA73/ref=pd_cp_mov_1

http://www.amazon.com/Bread-Roses-Pilar-Padilla/dp/B00005OSLC/ref=sr_1_1?s=movies-tv&ie=UTF8&qid=1374941408&sr=1-1&keywords=bread+and+roses

http://www.amazon.com/Matewan-Chris-Cooper/dp/B000068QP0/ref=pd_cp_mov_0

http://www.amazon.com/Silkwood-Meryl-Streep/dp/B0000AM6IS/ref=sr_1_1?s=movies-tv&ie=UTF8&qid=1374941815&sr=1-1&keywords=silkwood

See also Salt of the Earth, in Available Online tab