Zürich Airport, roughly 9km (6mi) north of the city center, handles domestic and international flights.
The journey from the airport to Hauptbahnhof station takes 12 mins by train. Up to nine trains an hour run between the airport and Hauptbahnhof between 06:00 and 24:00. Buy your ticket before boarding. This is a cheaper and quicker option than a taxi into the city which will set you back a hefty sum.
The busy Hauptbahnhof has direct trains to Stuttgart, Munich, Innsbruck and other international destinations. There are also regular direct departures to most major Swiss towns.
For drivers, the A1 is the fastest route from Bern and Basel; it also services routes to the north and east of Zürich. The A3 approaches Zürich from the south, along the shore of Lake Zürich.
There is a comprehensive, unified and extremely efficient bus, tram and S-Bahn system in the city, which includes boats on the Limmat River (although not cruise boats on the lake). Tickets allow you to switch between modes of transport as you like. There's a 24-hour city pass, and a 24-hour pass valid for unlimited travel within the whole canton of Zürich. Taxis in Zürich are expensive and almost always unnecessary; even high-earning bankers tend to catch trams.
Health and Safety
Street crime is fairly uncommon. However, do watch your belongings; pickpockets thrive in city crowds. The Swiss police aren't very visible, but when they do appear, they have a poor reputation for their treatment of people of non-European descent or appearance.
There is a heroin problem in Zürich, though you have to be a way off the main thoroughfares to notice it.