Scientology, what is it?

I hear so many diffrent things, and being a student of not just the sciences, but philosophy, and theology, I keep trying to figure out the truth. The information online is amazing but no two sites say the same thing. I'm not going to spend millions of dollars to find out I just bought the most expensive sci-fi book ever, so who and what are they? Based on a friend who worked at a office, south park was pretty accurate, but if that's true, how can so many people be behind it? They say thier not a religion yet thier a church with tax exempt status, don't most churches give away something, like the bible, even Mormons give away the book of Mormon, the bible, and DVD's. If there is something here and you know please hook me up, as any reader knows I'm looking at faith with an open mind, so please share with me.