The most famous hotel is the Sacher, of the cake fame (above link).
They just opened a new Meridien, which looks fabulous, and the Hilton Stadtpark has been newly renovated.
Salzburg: We loved the Kobenzl www.kobenzl.at Super romantic, but not in the city center. There is a very nice Sheraton in the city. A nice mid-priced Hotel is Hoelle www.hoelle.at we had family stay there and they liked it a lot.
The following is a repost of a Vienna tread from the other website...
Vienna is very easy to navigate and has great public transport.
There is tons to see, especially if you like arts and history!
http://www.khm.at/ Art History museum
http://www.belvedere.at/ Austrian National Gallery (all the major Klimt pieces)
http://www.schoenbrunn.at Schönbrunn castle Habsburg residence
http://www.hofburg-wien.at/ Imperial palace and residence
there is much more, these are the musts I'd say
The first district and most of the cool stuff is inside or close to the "Ring". The subway is great, runs every few minutes and from 5 AM until a little past midnight. There is also trams, they are ok but rather slow, and buses.
As for areas to avoid... of course being a big city there are areas that are not as pretty as others. But we have always felt safe everywhere and crime is very low.
I've got a few more must see sights..
and the opera house http://www.wiener-staatsoper.at/Content.Node2/intro.php
Shopping on Kärntnerstrasse
But if you go downtown, you cannot miss them anyways.
As for food, what Austrian cuisine does best (I think in the world) is pastry. Cakes, strudels, baked sweets. Most famous of course is the Sachertorte which you have to try at the Sacher cafe http://www.sacher.com/
But there are many other treats. Vienna is known for it's coffehouse culture.
A word on restaurants... this is Europe and people will smoke. Many restaurants do not even have a non-smoking-section. It sucks, I can't wait till they change that!
A fun thing to do as well is to visit a Heuriger - a typical winery with a tavern. Vienna actually has wineries within the city limits! http://www.aeiou.at/aeiou.encyclop.h...on?LANGUAGE=en
As for bikes... I think they have a pretty good network of bikepaths, maybe not quite as good as the NL, but don't take my word as I don't even own a bike.
For Tickets for something , the above link to the Opera, as well as this: http://www.musicalvienna.at/ (english button on top right)