All lectures take place in room SG 3.14 in the assembly building. You can see it directly at the bus stop. The entrance is between the Sammelgebäude and the lecture hall building of Wirtschaft/Recht. Keep left and walk towards the stairs, there are two staircases right next to each other, you can take any one. Go to the third floor and follow the sign Beyond Canon to the left. At that point, the seminar room is at the end of the hallway on the right. 
 
To go to the dining hall, exit the building and keep right and go up the stairs to the Forum. Keep right here and you will see the Mensa immediately on your right. You can pay by EC card.

From left to right: the "Sammelgebäude", one of the entries, the staircase, the entrance to the 3rd floor, the beyond canon sign