His church is large and growing, but interestingly, he also has an amazing following on the Internet, with millions and millions of downloads.
He is a hip kinda guy, but yet appears to be thoroughly grounded in sound doctrine. His hero seems to be Charles Spurgeon and he frequently refers to Dr. Wayne Grudem in his teachings, videos, and podcasts.
Mark recently finished a lengthy series called, "Doctrines - What Christians Should Believe". I have heard a number of these and enjoyed them immensely. Mark Driscoll brings a lot of whit, bathed in sound reformed doctrine. Set some time aside in the next few weeks to learn some of the important doctrinal beliefs of the Christian faith.
Here are links to the videos: