Depending on your area and the number of clubs running autocross, you should also choose the club with the course that best suits you and your car. Some folks don't have that option as there may only be one club hosting a weekly event. The group that hosted the event at the Air Base near here set up a course that was best suited for smaller cars due to the narrow width of the strip allotted to them. There's a group more towards the middle of the state that runs an autocross now on a bigger strip which is much better for larger cars and faster cars.
Just another variable to consider. You want to have fun and be safe and eventually be fast and consistent, but you also want to be comfortable with what you're doing and the course that your doing it on. The wrong circuit will always be wrong for your car no matter how proficient you become.
