Stockholm can be reached by car, train, boat and plane. There are 3 airports: Arlanda, Bromma and Skavsta. The fastest way to reach Stockholm city from Arlanda is by the Arlanda Express. All airports can be reached by a special airport bus line, the Flygbussarna. Information about the Swedish trains can be found here. The easiest way to travel in Stockholm is by the subway. Information about the public transport in Stockholm, including a journey planner, can be found here.
A map showing the meeting venue can be downloaded here
Some interesting links about Stockholm and Sweden: