Going back to the first post... If you haven't been to the 'ring then it is certainly well worth the trip.
I've been a few times and the feeling of driving around it is amazing. The place can be quite terrifying though.... but that is probably what draws so many people in!
It really is as simple as finding out when the public days are, drive there, buy a ticket and you are on circuit.
The place has its obvious dangers, but a trip can be done without any problems, if you keep things sensible.
I'm hopeing to get back there next year..
One of the best sites I've found, which tells you everything you need to know is;
http://nurburgring.org.uk