The classical way to reach Groningen is to fly to Amsterdam and from there to take the train. During the day (from 6:00 to 22:30), there are two train connections per hour from Amsterdam airport to Groningen. One at hh:23, which is direct, and one at hh:53, which is with change in Amersfoort. The waiting time in Amersfoort is 5 minutes.
At Schiphol you could buy a one way ticket to Groningen. Such a ticket can be used for any train connection that goes to Groningen that day. The price of such a ticket is about 25 euros (second class) and about 40 euros (first class).
When stepping into a train take care to chose a wagon that goes to Groningen. It is customary in The Netherlands that trains split during their journey, some of the wagons going in one direction and the others in another direction. This happens with the trains departing from Schiphol and from Amersfoort. The destination of a wagon is written at its extremities on the outside.
Once arrived in Groningen, from the train station to any destination in the city, you can take a train-taxi. For using the train-taxi, one has to by a ticket from the train station. The price of a train-taxi ticket is about 4 euros a trip, no matter the destination.
Hotels in Groningen. Please arrange your bookings directly with one of the hotels.