Read this one, Ward is one of the most reasonable and pragmatic anarchists I know and herein are gathered his writings on Anarchism as a theory of organisation. The book is constructed around his core ideas of a spontaneous order, autonomous groups, workers control and the federative principle and is persuasive, although I did not find it that compelling a read.
What sets this book apart from other Anarchist books I've read isnt simply that its much more contemporary but that its not simply a critical appraisal of government and certain sorts of authority, there is some positive advocacy of an alternative which is already in existence. I agree with Ward that there are powerful unstudied or unacknowledged social forces upon which those that are acknowledged are premised, such as the co-operation which makes competition possible, his idea that an alternative better society exists in embryonic form appealed to me as sensible. Besides Ward the only other anarchistic author I think is worth reading is Paul Goodman, particularly Drawing the Line Once Again
and the earlier book "Drawing the Line" in which Goodman says that the objective of social change should be to expand the sphere of individual free action as far as possible. Unlike a lot of anarchist, not to mention general political partisan, authors this isnt a book about preaching to the choir or maintaining or reaffirming a sort of ideological correctness, instead its more open and reaches out the general interested readers.
Ward's other books are as practical and pragmatic as this one but this is probably the best, if you are interested in political ideologies or some interesting social insights this is the book for you. If you are looking for an incendiary read encouraging the building of barricades right away perhaps another author is going to appeal like Bakunin, that's not what this book is really about.