http://www.heiser.net/documents/nurburgring/
How do I pronounce that?
The easy way is to just call it the Ring like most people do. But if you want to give it a shot, the 'Nür' part of the name sounds a bit like saying 'New-uhr', and the 'burg' is a bit like 'boo-org' although most English-speakers say it 'Ner-berg-ring'. The locals don't seem to care; they're pretty much used to you mangling their language.
You may find that many of the locals (and staff of the track) refer to the track more precisely as the Nordschleife, since that's actually the circuit you're racing on.
The written world can be a bit more confusing. You'll sometimes find Nürburgring written without the umlaut over the first 'u' (i.e. "Nurburgring") or sometimes with the 'u' replaced by 'ue' (i.e. "Nuerburgring") as this is a phonetic spelling of the word when the 'ü' can't be written (like in US-ASCII, used for URLs). For instance, the official Nürburgring web site is actually
www.nuerburgring.de.
