Gimp,
There is no business that you can start without some sort of investment. Whether that's money, even a few dollars, or time. You have to put in something.
I also disagree with you on the premise of you question. You can't just paste content online, earn a dollar per clicked ad and sit back enjoying margaritas on the beach.
Why? Lots of reasons.
First, people need to find your site. Driving traffic requires money or effort. You have to either do CPC or other advertising, or you have to create compelling content and contribute to other sites via comments or blog contributions. Alternatively, you can drive traffic from the real world by doing something that makes people give a shit.
Second, the click-through rate for a great ad on your site is less than 1%, and is continually going down. You'll likely earn pennies, not dollars via AdSense.
Lastly, most free services on the web, especially hosting, are ad supported. Ever tried the free hosting on GoDaddy? Ya, there's a giant banner at the top covering up your content. Implementing a non-legitimate workaround, by covering the add up with content, would be an investment in and of itself.
I hate to say this, but man, there's no easy way to make money or build a business that matters. You have to work. I regularly work 60+ hours per week, if not more, and definitely don't get paid for most of it. It's the sacrifice you have to make in order to make something bigger than yourself.
In conclusion, there is no zero-investment, minimal-knowledge required, from home, quick return business. Even drug dealing requires knowledge, skills, investment, and chutzpah.