PLANE
Many European airline operators fly directly to Zagreb. You can check all of them on following link of Zagreb Airport.
http://www.zagreb-airport.hr/Airlines-33.aspx

Additionally, several cheap fligths operators fly directly to Zagreb or other cities in Croatia (Rijeka, Pula, Split, Zadar).
For cheaper deals check:
www.croatiaairlines.hr
www.easyjet.com
www.germanwings.com
www.wizzair.com
www.ryanair.com
 

TRAIN
http://www.raileurope-world.com/destinations/cities/Zagreb
http://www.hzpp.hr/Default.aspx?sec=282

 

ACCOMODATION
Special deal for accomodation during the workshop will be posted soon!