As the University campus is no more than 10' on foot from the main station, the train is certainly the best way to get to the campus.
Namur is served by quite a lot of train lines. Just take a look at the map of the Belgian Railways. The main lines come from Brussels, Liège, Tournai, Koln, Luxemburg and Paris.
Trains commute between Brussels and Namur twice an hour. Same from Liège, Charleroi and Mons.
For complete journey planning (timetable and fares) visit the belgian national railways web site (SNCB).
If you live in the area surrounding Namur, about twenty bus lines (some of which being Express such as the line 56 from Couvin) can drop you very near the campus or at the train station square. In town, about ten urban lines with frequent journeys allow you to travel within the city very easily.
The regional public transport authority TEC has a web site that allows you to gather information about timetables and fares.
If you arrive at Brussels International Airport (Zaventem), you can easily reach the train station after exiting the customs : take a rolling staircase at your left and go down to the train station.
Take any train, change at Brussels North for a train to Namur (see national railways web site). There are 3 trains per hour, the schedule repeats hourly until 23h.The fare is 9,1 € for a single ticket (free for children under 12).
If you are arriving from Charleroi airport. At the Ryanair counter in Charleroi airport you can buy a ticket valid for any Belgian destination for 10,50 €. This ticket covers a journey in a TEC bus (from the airport to Charleroi-Sud train station) and a train journey (from Charleroi-Sud to any station in Belgium).
If you are going to Charleroi airport, ask for ticket code C61 at the train station. With this ticket, you can take the train to Charleroi-Sud station and then the TEC bus (line A – platform 2) from the station to the airport (Gosselies).
University parkings are only for staff members. One of them (located rue Henri Lemaître) is accessible with this guest card. Please note that it is impossible to reserve parking slots and therefore the availability will be on a first-come, first-served basis. Do not forget to print the guest card and present it at the gates.
Otherwise you will have to park in the city (neither free nor cheap). For those interested, the city of Namur has opened a park and ride area along the river Meuse. You can leave your car over there and take a bus shuttle to the center of the city (10' ride for only 2,00 € all inclusive !).
From the motorway E411 (Brussels-Luxemburg)
Directions to the parking (accessible only with the guest card):