Peter Maurin's role in instigating the Catholic Worker movement makes his Easy Essays a must read for those interested in Christian Anarchist thought and nonviolent activism. Maurin meant these essays to be spoken aloud, not read privately. Actually, I kept hearing Bob Dylan's voice in my head while reading.
Dorothy Day's a saint in my book. So, any resource that helps me better understand her Catholic Worker movement belongs on my reading list. Still, I would read Dorothy first, and Peter second.