Erasmus in Humboldt U. zu Berlin

As I said in my profile I would need some help as an incoming student. If someone knows wheter all the classes are in German, how many ECT (credits) are every subject, how many subjects do I have to take, the list of the avaliable languages that an Erasmus student can choose... would be very helpful because I am a little bit lost with the University page. Also, if u know where to live there, the cheapest option... would be awesome too. Danke schön!.