Every reasonable-sized town in southern Germany (even those with no tourists) has a municipally funded tourist information centre, some of which are stand-alone operations, while others are twinned with a kind of local residents' information point. Only very occasionally will you come across staff who don't speak English and the vast majority of those charged with aiding tourists on their way are knowledgeable, friendly and efficient. Websites operated by tourist boards vary wildly in quality.
Good websites for your pre-trip research are www.bayern.by and www.germany-tourism.de.
Each region/product/Land also has its own dedicated website:
Baden-Württemberg Tourist Association (www.tourism-bw.com)
Black Forest Tourism Association (www.schwarzwald-tourismus.info)
Eastern Bavarian Tourism Association (www.ostbayern-tourismus.de)
Romantic Road Tourism Association (www.romantischestrasse.de)
Franconian Tourism Association (www.frankentourismus.org)
Tourism Association Allgäu-Bavarian Swabia (www.bavarian-alps.info)
Upper Bavarian Tourism Association (www.oberbayern-tourismus.de)