One very useful resource for finding material for case studies is the website http://civilresistance.info maintained by Howard Clark, and including in full the bibliography People Power and Protest since 1945 and its ongoing online update: http://civilresistance.info/bibliography/update as well as the texts of four out-of-print books. The final section of the bibliography is devoted to Preparation and Training for Nonviolent Action.
The four books online are:
Civil Resistance - written by former WRI chair Michael Randle, with a chapter written after the original publication;
Challenge to Nonviolence - edited by Michael Randle and including three more chapters than the printed version;
Living the Intifada - Andrew Rigby's 1991 study of the first intifada, which he characterises as more or less an unarmed struggle;
Thirty-One Hours: the Grindstone Experiment - a 31-hour training experiment in nonviolent social defence.