Hi Bayerischer Motorist,
here are my "golden rules of autocrossing" (in no particular order):
* when you walk the course, draw a map because at the end of the walk (and specially before your run you will have otherwise forgotten everything)
* ALWAYS try to look at least two turns ahead
* your foot is either on the gas or the brake, try to avoid coasting
* when your car is understeering like hell, this doesn't mean you need new tires or a new alignment, this means you are too fast in the turns (that took me VERY long to learn), I was the "king of understeer" for a long time
* don't be nervous, you'll meet 99.99% very nice people there, who are happy to help and give advise
* and most of all: HAVE FUN
btw: for insurance reasons here in CA you are only allowed to hitch a ride with an instructor, so don't just jump into anyone's car
and last not least let me create some traffic to me autocrossing on YouTube:
http://www.youtube.com/watch?v=Yi0CdWJoIQg
Enjoy
Christopher