What is the best way to clean up an oil spill and why?

Well, I don't know if you're talking about a large scale oil spill, like from a boat, or one from a car but but considering it's 9:12 and you need this answer by 9:30 tonight, I will do my best to help you. If it is a small spill like from a car, you can use kitty litter which will soak it up. Then after that you can use dish soap to lift the stain in the pavement. That's really all I can say... Hope this helps!