Rules for Radicals by Saul Alinsky
The author compares Rules for Radicals to The Prince by Machiavelli. The comparison is apt. Both books are about power, its uses, maintenance, and acquisition. Saul Alinsky, as indicated by his own words, cared about power and winning. If honor and morality had to take a back seat, so be it. I don't know for sure, but I suspect he was a bad man.
That doesn't mean that the techniques described in this book are ineffective. I've never been a community organizer, nor do I have any desire to ever be one, but in my much-less-than-expert judgement, Alinsky's rules seem to be useful. I recommend this book to anyone who is interested in community organizing.
I also recommend this book to anyone else who cares about self-government and keeping his personal liberty, for the same reason that I have long recommended that everyone read The Prince. Be aware that anyone who seeks power has either read The Prince or is being advised by someone who has read The Prince. You need to read it so that you are aware what the SOBs are up to, even if you have no desire to apply the principles yourself.
Now that I have read Rules for Radicals, I'm reasonably sure that the same thing can be said about it: The SOBs are using it, so you probably should read it in self-defense. Fortunately, it's an easy book. The prose is clear and contains some humor to help it go down smoothly.