I'm not exactly an experienced autocrosser, but I'll post up my 2 cents.
The best starting place I found is an article written on Honda prelude.com by Jamie, their racing moderator. Got to Honda Prelude.com, click Resources, then General, then Racing. He has a very good primer, it handles all the basics (ie what is autocrossing, etc.)
As to why to go first and mod later, I can give my reasons. The first is that I know I can't drive my car to the limit. There's no way one can expect to get on an autocross course and drive fast. You have to learn driving technique. I know the first time I went out, it felt like I was at the limit, tossing the car around, etc., but I was one of the slowest cars there. Nobody can drive like an autocrosser without practice. I suggest if you plan to autocross and modify, go the first time stock, you'll realize how slow you are. Another way I realized it's all about the driver is when I saw a stock 4th gen prelude (driven by Jamie from Honda prelude.com) run 2 and a half seconds faster than a Ferrari 328 GT. Try and blame the car when it's a Ferrari. The last reason I'm not modding til I can drive at the limit stock is because when I do modify, I'll know exactly what changed and how much. If you start out with new springs, shocks, swaybar, etc. how do you know what each one does.
As for having to look cool, that was never a problem for me, which is good because there was a Ford Focus consistently faster than me this past season. The one good thing about that is there's no pressure, you can concentrate on driving 'cause you're already at the bottom of the pack.
I guess that's it, since everyone's probably I'll stop.
A forum community dedicated to Honda and Acura owners and enthusiasts. Come join the discussion about performance, modifications, concepts, reviews, classifieds, troubleshooting, maintenance, and more!