Currency
The only accepted currency in Norway is Norwegian krone (1 euro is app. 8 kroner). At most places you can pay by debit or credit cards, and if you need cash, it should not be difficult to find an ATM machine (called minibank in Norwegian) nearby. If you do need an exchange office, there is one to the left from the exit from customs control at the airport. Note that it might be closed on Sunday. In the city the easiest is probably to go to one of the two Forex offices at the Central Station, one is in the main hall, the other is at the Airport Express Train terminal. They are definitely closed on Sunday.
From airport to hotel
We recommend to take the Airport Express Train (Flytoget) to the Central Station (Oslo S) and then to take a taxi to your hotel. If your flight is delayed and you miss the last train, there will always be a bus (SAS Flybussen) going to the Central Station. Taking a taxi directly from the airport is quite expensive (around 70 euros fixed fare, 150+ euros meter fare), but it can make sense if at least two people share one taxi and pay a fixed fare.
You can find more information on how to get to Oslo here. If instead of a taxi you prefer to use public transportation, you can plan your trip at Ruter#.
Conference venue
The conference will take place at the Department of Computer Science of Oslo and Akershus University College of Applied Sciences (until recently called Oslo University College (Høgskolen i Oslo)). The address is Pilestredet 35. The building is just 500m from Thon Hotel Munch, where most participants are staying. Here are some useful links:
How the building looks like
Where it is located on a map of Oslo
Another map (with Thon Hotel Munch indicated)
View in front of the main entrance of the building
If you are staying outside downtown Oslo, use Ruter# to find a route. In particular, if you are staying at a guest-house at the campus of the University of Oslo, you can take the subway (T-bane) from Blindern to Nationaltheatret and then walk; an alternative is to take the tram nr 17 or 18 from John Collets Plass to Holbergs Plass.
Enter the building through the rotating door, and you will find the registration desk in the atrium. In case you are late, directions to the auditorium will be clearly indicated.