Salzburg and Vienna trip

I'm not sure if you've picked up Rick's guidebooks for this trip, which is where he publishes his hotel recommendations. For instance, in the new town area of Salzburg around Linzergasse and the Mirabell-Congress parking garage, he lists a few hotels with quad rooms. Those probably will have the three total beds you need, but you have to confirm that level of detail with the hotel when booking. Similarly, if you tell an online booking site that you have four adults, you still have to delve into the resulting bed configuration details.

It's be awhile since I've been to Salzburg, but we stayed 3 miles out of town on a farm the last trip. It was an absolutely beautiful private home on a local bus line. B&B's abound in this very popular tourist town.

We were again in Vienna earlier this year. We always stay at K&T Boardinghouse, which is where Rick Steves used to stay when in town. They now have a second location closeby, and it's about 100' to the entrance of the Mariahilfer Strasse Metro station. That's just 1 Metro stop west of The Ring. The rooms are huge, and the price is right @ 79 Euros.

See: http://www.ktboardinghouse.at

You asked for suggestions for one day of sight-seeing in Salzburg.
Rick's guidebook describes Salzburg sights. One of these is Hohensalzburg Castle/Fortress, above the city.

I believe that the historic center of the city is a World Heritage Site.
There are many churches featuring baroque architecture, Salzburg Cathedral is one of these.
Also the gardens at Mirabell Palace.
Happy Travels!

I have stayed at Haus Ballwein which is located on Moosestrasse on the outskirts of Salzburg. She rents out apartments which might suit your needs. Here's the website: http://www.haus-ballwein.at/en_our-house.htm You can catch a bus right in front of her B&B to the center of town.

Just as a note -- the beds in hotels we have used in Munich, Salzburg and Vienna have all been twins -- sometimes pushed together to look like a double, but separate mattresses, separate bedding. Think your sons could deal with that?
In Salzburg we have used Drei Kreuze and Goldenes Theatre Hotel both near Linzergasse parking garage -- great breakfast at both.

Walking around Getreidegasse and the old town area in general is always lovely. There is also a nice set of walks above the castle - think the area is named Moenchsberg. There was a lovely and very small restaurant up there as well along the walk. If I remember it sits on a precipice overlooking the old city center.

If you have a car I suggest to look at inns in the belt south of Salzburg - places like Wals or Anif, that often offer better value for money than accomodation in the city.