I have just started learning about AutoCross. Basically - you set up a course using a wide open space and the orange cones you see on road construction sites. Mostly, the cones are set up as "gates". These gates range from a very simple setup of two cones(which you must drive between) up to very complex layouts with many cones.

Some cones may be laid on their sides to designate a pointer. These are only setup to help the driver know which way to go to stay on the course. Other cones are set upright and you will have time deducted from your final time for every one of these cones you hit.

If I had to guess, everyone has their own specific reason for racing. Some folks are very serious about it while others do only for fun. From what I have seen so far - it's a great learning experience for anyone who has never driven hard. If you have never "fishtailed" or spun-out your car... or if you simply want to learn to drive hard, then Autocross gives you that chance. The risks are minimized by staying in large open spaces and by following some simple rules and guidelines. We also wear Snell rated helmets in case there is an accident where the extra protection might help out. I autocross because it's fun, because I love driving, and because I want to learn to drive better.

I am the webmaster of the local SCCA Red River Raceway site, check it out. It explains a good deal about about autocross and has some helpful links.