I agree with many others that there is a lot to see in Munich and Salzburg is also worth a day-trip. Two other options, especially if the weather is nice, are two monasteries just south of Munich: Ettaler and Andechs. You can reach both from Munich by train and bus.

To find tourist information online from German cities, just try this: www.nameofthetown.de If that doesn't work, try google. Most of them have tourist information on the town web site. Good luck.