Schübel-Auer is a "Heuriger", which in German means "Winery"... or in this sense "Wine Garden"…read more There are dozens of these wine gardens in the outer areas of Vienna...I highly recommend visiting at least one!
Schübel-Auer is easy to get to: take Tram D heading north all the way to the end will drop you in front at the Nußdorf Beethovengang stop. This will also get you an interesting look at the less glamorous side of Vienna for the everyday locals. (Next door is another Heuriger called Kierlinger, but I didn't a chance to visit this one)
Mostly locals, with a just a few business tourists. All the staff did speak pretty good English. Rick Steve's guidebooks recommend this Heuriger, so they're probably prepared for tourists.
First, find the food counter, you'll find items labeled in German and English. We got there later, after 8pm, so the selection wasn't as good, but still good enough. Figure about €10-15 per person, depending if your appetite. I learned the hard way that the pastrami was served cold, but it was till pretty good. Nothing fancy, but everything we picked was good.
Second, grab a table, any free table. A waiter will come up for drink orders, aka wine order. Typically there's only 2-4 choices. But the best part is, its cheap! A half liter is only €6-7, or a glass for €1.70. Try doing a 50/50 mix with white wine and mineral water: "Gespritzer", which is popular among the locals.
Third, eat, drink, and relax...