I used Rick Steves' guidebook for my recent trip to Vienna and Salzburg and found it to be an excellent source of information for a first-time traveller. I'd suggest buying a copy.

If nothing else, you will want to familiarize yourself with the subway (U-Bahn) and Tram routes and stops, as I suspect you will find this a convenient way to get around. Taxis are also very convenient and easy to find.

I did document my trip experiences in a Trip Report, read on if you have a few minutes to spare...

http://flyertalk.com/forum/showthread.php?t=448474