I've been detailing cars for over 20 years. First off, never, never, never dry off a car that is wet from driving in the rain, snow, or from wet roads. Not only is the car covered with water, but also grit, sand, and road debris. As you wipe the car dry, you are grinding that debri and dirt into and accross your paint. As much as it hurts, let the car dry and wash it properly when things dry up. If you just can't bear to let the dirt dry on it, wash it with soap, yes, even in the rain if you must. If your car is waxed, letting it dry won't harm the paint.

Also, never wipe dust off or wax dust off your car without first using a tool such as a California car duster. They aren't perfect, but they do remove large amounts of dust without scratching your car if used properly. After the dust is off, then use a detailer spray or wax.

For light scratches, try using a cleaner wax like Zymol and good ol' elbow grease. If that doesn't work, use a buffer. If the swirls and scratches are deeper, use a scratch remover wax like Scratch Doctor. I wouldn't use a rubbing compound unless it is a very small area with very deep scratches. Lots of hand rubbing and use of a buffer do wonders. As for the buffers, I've never had to use an orbital buffer. I use a vibrating/rotating car buffer. You can do serious damage with a professional orbital buffer unless you know what you're doing.

Hope that helps!