Mark Driscoll is the senior pastor (and founder) of Mars Hill Church in Seattle. He is also one of the most gifted speakers I have ever heard at explaining the Bible to young adults. This book is basically the history of Mars Hill Church, from his point of view.
One of the things that is so refreshing about Driscoll is his complete and disarming honesty, often expressed with a great sense of humour. So when he's thinking about systems of church government, he is happy to say that after considering the congregationalist model, he sees slightly more Biblical justification for the government of church by unicorns. It's quite possible that some people would find his thoughts about them offensive. But he extends the same standards to himself - if he thinks he stuffed up badly, he'll say so.
What he doesn't do, though, is toe any party line. He doesn't seem to condemn ideas just because everyone else condemns them (drinking, smoking, tattoos). But neither does he go along with stuff unquestioningly - he tries to bring everything before God and measure it up against Scripture.
He is by no means perfect, and Mars Hill Church isn't perfect either. But God has used them both greatly, despite and sometimes even through their imperfections, and I thank God for that.