The conference is hosted by the Institute of Computer Science, the University of Tartu.
The University of Tartu is located in Southern Estonia, in the second largest city in the country, in Tartu (some tourist information is available here).
There exist direct flights to Tallinn (the capital of Estonia, 180 km from Tartu, frequent bus connection) from many cities. For information on the connections, see the web homepage of Tallinn Airport.
The best way from the Tallinn airport to Tartu is a bus. SEBE bus company's Täistunni Ekspress (Hourly Express) bus departing to Tartu stops at Lennujaam (airport). The Tallinn airport is quite small. You could easily find a bus stop. Departure times are 7:05, 8:05, 9:05 ... 19:05, 20:05, 23:05. The buses are quite comfotable (WIFI connection, for example). Information about all Estonian intercity buses (choose LENNUJAAM/TALLINN - TARTU).
There are flights to Tartu via Tallinn and Helsinki. Tartu Airport information.
A more detailed description of how to get to Tallinn and Tartu and some basic information about Estonia in general (money, time, electricity, Internet etc.) is available here.
You can also get to Tartu via Riga (the capital of Latvia, 250 km from Tartu, infrequent bus connection). Riga Airport information.
Estonia belongs to Schengen area. You can check whether you need visa to enter Estonia or not on webpage of Estonian ministry of foreign affairs.