Jim, Both Arizona sanctioning bodies (NASA and PASA) have their own licensing process and dues. First you must take and pass a driving course with instructors from their respective groups. One group frequents PIR more and one Firebird more. Both are comprised of fine, well trained people, drivers and safe cars.
NASA:
http://www.clubracingaz.com/
PASA:
http://www.proautosports.com:80/
You will need basic safety equiptment (helmet, seatbelts) and until trained and licensed will be limited on passing.
As a group the AZ Cobras have been through several days/classes/events.
AZ Bob