Arriving in Helsinki
Helsinki City information page how to arrive to Helsinki: http://www.visithelsinki.fi/en/come/welcome-helsinki/arriving-in-helsinki
Arriving in Helsinki-Vantaa Airport: https://www.finavia.fi/en/helsinki-airport/arriving/
Transportation from/to Helsinki-Vantaa Airport: https://www.finavia.fi/en/helsinki-airport/to-and-from/bus-service/
Accommodation
The City of Helsinki offers a list of hotels near the city centre: http://www.visithelsinki.fi/en
Useful information for visitors can be found on the same site.
Here are some hotel suggestions which are quite close to the venue:
Lower-cost accommodation:
Helka Hotel (about 2 km (22-25 min. walk) from the venue)
Other hotels: