To get from Amsterdam airport (Schiphol) to Utrecht by train, see www.math.uu.nl/address/schiphol-utrecht.
From the central station (or from the Mitland hotel), take bus 11, in the direction of De Uithof / WKZ (it leaves every 10 minutes). Exit at the stop "Botanische Tuinen". From here, you will see the Minnaert building.
The Mathematics building (Budapestlaan 6, see Google Maps), where a large part of the week will take place, is situated behind the Minnaert building, and can be entered through a bridge from the Minnaert building. The library is situated on the top floor, computer facilities are on the fifth floor, and other locations for the study group are on the sixth floor and in the basement.
People staying in Utrecht who have reserved a room at the Mitland hotel (locate at Google Maps) can also take bus 11 to the university campus ("De Uithof").