Most has been said before, so I'm not going to say it all again.
And be very carefull with Nurnberg and N?rburg, they are quite far from eachoter. You wouldn't be the first foreigner who makes that mistake. If you need to take a plane, go to Frankfurt. It's the closest big airport IIRC.
It's all been discussed
here before, so I'd advice you to read this through.
If you still have questions I'd be happy to answer them (I've already been there a couple of times before).
The site (
http://www.nurburgring.org.uk/ ) is absolutely the best place for information. There's also a list of rental companys which "allow" you to drive their rentals at the Ring (be sure you don't tell them this).
Also, keep in mind that the Ring is a one way public toll-road, and therefore you need to have a driving licence that is accepted in Germany and you have to be 18!!!
Oh and just for the info, the N?rburgring consists of 2 parts. The northern loop is the famous Nordschleife and the south circuit is the S?dschleife (GP-circuit). The one you will be able to drive on, is the Nordschleife.
The dates it's open for Tourist drives can be found
here . You can set the language to English, so you'll understand all of it.
And again, have fun, but be very carefull.
Greetz Johan