The main airports are the intercontinental airports of Milan (Malpensa, Orio al Serio and Linate) south of Lugano in Italy, and of Zurich-Kloten north of it in Switzerland.
To research further how to find your way to and from these airports, or any other, I recommend the excellent site To and From the Airport. (Some cheap airlines I happened to come across while researching this that operate in or to Switzerland, in addition to the ones mentioned above, include airberlin, helvetic and brusselsairlines.)
Lugano has a convenient small airport at Lugano-Agno with a number of direct connections to and from Geneva, Zurich, Rome, and a few other European cities.
A regular shuttlebus takes you from the Airport at Agno to the centre of Lugano, or you can walk the short distance to Agno FLP train station; trains are every 15 - 30 minutes at most times and take some 20 minutes. If you return via Lugano-Agno, you may like to know that its small size makes check-in quick; a few years ago, a plane actually halted on the runway to let a late-arriving passenger run to catch it and while they may not do that today, Agno is not an 'arrive three hours early' airport.
Lugano has very good rail connections to and from many other European cities. Many of these connections are by the spectacular "Cisalpino" tilting trains, which link Lugano with Zurich, Stuttgart, Como, Milan, Bologna, Florence, Verona, and Venice.
You can consult the schedule of the Swiss Federal Railway here. To get a list of the best train connections from Milan Central Station or Zurich Airport Station to Lugano, enter "Milan" or "Zurich Airport" as places of departure, as well as the approximate date and time of your planned departure from the train station. Once you have selected a connection, you can also download a personal timetable booklet in PDF format, Palm format, Psion format and other formats, or can request that it be sent to you by email.
The Swiss railway site shows train connections provided one of the ends of the journey is in Switzerland (if both ends are, you can buy and print your ticket by credit card - N.B. last I looked they did not take debit cards). It also shows
and it will compute multi-stage journeys via train, bus, whatever. Do not be concerned where it shows tight connections; Swiss postbusses and trains are scheduled to connect to each other and if the site shows a connection, you can confidently expect to make it.
Use Swiss maps to plan journeys, to find the bus stop that you want, etc. (these are the same maps you can reach from the railway site, but if you are unfamiliar with the area it can help to study the maps first, then go to the railway site). Lugano main railway station is in the centre-middle-left of this map. Scale down one step to see the airport runway just north-west of Agno in the lower left of the picture. The various symbols that appear (at appropriate scales) identify bus stops, railway stations and other facilities; move the mouse over them to get an explanatory popup.
Currency information: Switzerland is not in the euro-zone. Bring Swiss francs, not euros, for your stay (in practice, major tourist and travel outlets will often accept euros but expect a poor rate for small transactions). Italy, Germany and France are in the euro-zone; Milan rail station train tickets can be bought by credit card. Tickets to it from Orio al Serio on the shuttlebus can also be bought by credit card from the kiosk in the arrivals hall. The Malpensa shuttlebus should be booked in advance on the website but is paid for on the day of travel, priced in euros but I assume Swiss francs are also accepted (and credit card?). For other journeys with a stage in these countries, review whether you will need some euros.
Adapter information: Swiss power sockets are not the same as most European ones. The conference organisers will have some European-to-Swiss adapters and some European-style socket multipliers (and at least one UK-style socket multiplier). Adapters that convert European-to-Swiss are cheap in local shops (7 Swiss Francs) and work OK when stuck on the end of an Elsewhere-to-European adapter; I would imagine a typical hotel would have some on-hand (N.B. I do not know this). I have sometimes managed to force a European-style adapter into a Swiss socket and get power, but the adapter was usually never the same afterwards and if it is too rigidly built you can't do it. :-)
Travel pass information: anyone planning to arrive early or stay later for a holiday may like to know that in July and August the Ticino travel authorities usually have a half-price offer on the one-month intra-Ticino travel-card, called the arcobaleno or the abbonnement. (Ticino as the locals call it, or Tessin as other parts of Switzerland call it, is the canton containing Lugano.) Information is here but if you cannot read Italian, then only look at the zone page (Lugano is zone 10, to reach the airport at Agno you also need zone 11, etc.) and at the full-price costs for a given number of zones. The card can be bought at any rail station or post office and provided the specified start date is in July or August, then for half the cost shown you get free travel in those zones for the next month on busses, boats and FLP trains (N.B. not mainline trains; funiculars may be free or half-price). Since the railway site will tell you the cost of specific bus, FLP train and boat journeys, you can decide whether this would benefit you.