Go here.
http://www.scca.org/Club/DriversScho...0&x=030|020&~=
It can get confusing but the gist of it is; 1. Join SCCA. 2. Apply for a novice permit. 3. Bring a race prepared car (you can rent these and let someone else worry about taking care of it) to an SCCA novice school. With your previous experience you may very well get signed off to race after your first school. 4. After finishing 2 regional races you can get your regional completion license. 5. 4 more and you can get your national competition license.
I am currently between step 3 and 4. I bought one of these.
http://www.scca-enterprises.com/spec_ford.html It's a blast to drive. There's a lot of track side support for it. The cars are all equal so I can focus on the nut behind the wheel.