Flughafen Wien Schwechat is Vienna's international airport and is served by over 80 airlines. Austrian Airlines is the national carrier. Bratislava's MR Štefánika Airport in Slovakia is only 60km east of Vienna, making it close enough to be an alternative to Schwechat. There is a number of options for shuttling from the airport as well as major car rental desks.
Vienna has no central bus station so if you are arriving by bus, your arrival destination will depend on which company you're travelling with. Eurolines handles most of Vienna's international bus connections and covers a plethora of destinations between England and Turkey.
Vienna has a comprehensive and unified public transport network that is one of the most efficient in Europe. Flat-fare tickets are valid for trains, trams, buses, the underground (U-Bahn) and the S-Bahn regional trains. Services are frequent, and you rarely have to wait more than five or 10 minutes.
A popular mode of transport in Vienna is cycling. Over 700km of cycle tracks criss-cross the city, which means you're often more concerned about running into pedestrians than being run over by cars and buses.
When it comes to thoughts of driving, you're better off using public transport. The streets are a complex system of one-way streets, the Viennese are particularly impatient drivers and parking is difficult and/or expensive in the centre.