Zurich airport is one of the main airports in Europe with excellent international connections. Once you arrive in Zurich, we recommend to take public transport to the city center. You can use the same ticket in Trains, trams and busses, so it does not matter what you choose. The train departing from the lower floors of the airport will take about 10 minutes to the city center, while the tram departing from the upper level will take about 35 minutes (the number 10 tram also passes by ETH Zurich on the way to the station). Of course taxis are also available for those who do not want to deal with public transport.
Zurich is well connected by train, and thanks to the recently finished tunnel, the connection to Milan has improved quite a lot. Be careful about Munich. Although it is quite close (300km), the train connection is complicated and it takes quite some time.
Basel is actually quite close to Zurich (about 1hr by train with a train every half an hour) and there is a bus service from the Basel/Mulhouse airport to the Basel train station making it quite practical to fly to/from Basel airport. It is a cheaper airport, that is why quite a number of low cost flights arrive there. Geneva is the other alternative airport, and while you can find many (and cheaper) flights to Geneva, it is still a three hour train ride from Geneva Airport to Zurich, so we would not recommend you to travel through Geneva.
Zurich is quite expensive to stay. As long as you are within the city zone, you will not have much trouble reaching the WOSH venue. The city is well connected using public transport, and even some places that seem a bit further away on the map may actually have good connections. There will also be several options with services like AirBnB. We recommend booking early.
First rule of Zurich, do not drive in the city, use public transportation. There are not many parking spots avaialable, those that you find are expensive and the access by cars is usually tricky and difficult. For most destinations you will be faster on foot or by public transport.
The main way of getting around in Zurich is using the public transportation (mostly trams). The good news about Zurich is that the same public transportation ticket is valid everwhere busses, trams, boats, trains as well as the few funiculars. The price is dependent on the number of zones you travel. The city is a single zone (110), the airport is an additional zone (121). Unless you want to go to Uetliberg to enjoy the view over the city, you will need a combined Zurich/airport ticket (110, 121) when you arrive and city tickets when you are in the city.
You have basically two ticket classes. A single ride ticket which is valid for 1 hour (costs 4.40 CHF / 6.80 until airport) and a 24 hour ticket (costs 8.80 CHF / 13.60 CHF until airport) which is twice as expensive. For very short distances there is also a 'cheaper' short distance ticket "Kurzstrecke" for thirty minutes (costs 2.70 CHF). This would be valid from the main station to ETH/Universitaetsspital. One additional ticket is for the Polybahn, the very short funicular form Central to the ETH Main building for only 1.20 CHF.
If you want to make a few trips, you have the opportunity to buy them in six packs. You will then have to stamp them before boarding the transport and save about 10% of the price. Note that you can stamp multiple times when travelling for more than one person.
There is also the Zurich Pass for 24 or 72 hours (27/53 CHF). This ticket not only includes public transportation (including the airport), but also rebates for most of the museums and attractions in around Zurich, it might be a very good option for your companions, while you attend the WOSH, they can enjoy Zurich.
If you look at a map, you will see that the ETH main building is very close to the station. However, it is also a bit up the hill. That is why most of us take a tram or Polybahn going up. If you re studying how to get around, beware of the hills.