The Secretaría de Turismo Bariloche office in the Centro Civico is the place to go for tourist information, yes. But I'm including it here as the meeting point for my favorite Bariloche walking tours.
Nothing beats a good walking tour to get the feel for a city and it's no different down here in Patagonia. The tour guide and creator is an expert in the region and is also very charming in the way a good tour guide has to be.
I went on the German Footprint Tour and highly recommend it for history buffs. It, of course, goes into the Nazi history here that I KNOW you're curious about but it also goes beyond that. There were 3 total waves of German immigration to Bariloche!
He also offers hiking tours and other themed history tours, check them out:
German Footprint - Fascinating Bariloche history
History of President Peron in Bariloche
Patagonia’s Indigenous Peoples – Learn all about this region’s original inhabitants
10 Secrets of Bariloche – A great introduction to Bariloche, learn the city’s best kept secrets.