I just finished Rodrigo Nunes's book Neither Vertical Nor Horizontal. It's the most useful piece of political writing I've read this year. It's theory-heavy, excavating the history of left organizing, its failures, and the theory that drove them beforehand and tried to explain them after.
The theory is necessary and well-used. The book tries to answer the question of how we organize and navigate between the failures of old left parties and vertical organizations and also of the alterglobal/plaza/occupy movements, trying to come up with a functional toolkit for organization design.
He ends up with an ecological model, a notion of distributed leadership and organizing cores, and the idea that a vanguard that inspires change should be seen as a function or at most a role, not an identity. There's also a useful information-theoretic frame for the fitness of ideas.
This is not a particularly accessible book. You don't need to have read the sources, but if you don't know who Hardt and Negri are, it's going to be challenging. I would love to see a shorter gloss eliding some of the theory and history in favor of a directly usable text for people doing the work.