The main venue for the Amsterdam Colloquium is CWI, which is located at Amsterdam Science Park 125. This and other relevant locations can be found on the map below (click here to view a larger version).
The main conference venue is within walking distance from the Amsterdam Science Park train station. The locations for the Beth lecture and the reception are a 15m walk from Amsterdam Centraal train station. They are also reachable by tram (line 4, 9, 14 or 24 to Spui, click here to see how to walk from the tram stop).
There is a ticket system for all public transportation in the Netherlands called OV-chipkaart. You can buy an OV-chipkaart at the NS Rail ticket desk at Schiphol or from a machine at Central Station. You need a minimum of €20 on your card to get on the train (it won't let you check in at the station otherwise). For buses and trams the minimum is €4.
Don’t forget to always check in and check out when taking a train, bus or tram. If you forget, your deposit will be gone. At Schiphol, you can check in and out at the yellow poles at the top of the escalators, at CS in the hallway downstairs, and on the bus or tram with the driver or when getting off at the backdoor.
You can plan your trip using 9292 or Google Maps.