It is quite easy to find a room or an apartment on the private housing market. Many students in Berlin live in shared apartments (WGs) and there is a relatively large supply of rooms. You find these offers on the internet (e.g., Studenten-WG or WG Company), in various Berlin magazines, or on notice boards in different places of the university. As Freie Universitaet Berlin is located in Dahlem, a residential area with many villas, rooms/apartments around the university are rare and normally quite expensive. For that reason students generally commute from other parts of the city, with 30 minutes to one hour commuting time on public transport being nothing unusual.
Rents in Berlin normally start around 250 Euro, shared apartments tend to be less expensive. On signing the lease your landlord will probably expect a deposit of three months, reimbursed with interest at the end of tenancy as long as nothing has been damaged. Sometimes a commission or a compensation for furniture is requested; therefore, make sure that you bring enough money with you.
If you arrive in Berlin and have not yet found an apartment or a room you will need cheap short-term accommodation at either a youth hostel (Jugendherberge) or a guest house (Jugendgästehaus).
Within 10 days after your arrival in Berlin, you need to register with the local authorities (even for a temporary stay). The proof of residence registration is needed to open a bank account. You can ask your landlord, residence hall director, or the neighbors which registration office (Bürgeramt) you should go to.
the official registration form (Anmeldung beim Bürgeramt) which you can download from here or obtain in the residence halls or at any stationary store;
your passport or identity card.
The opening hours vary from one part of town to another. On the internet you can find all registration offices (Bürgerämter) and their opening hours. All students from EU Countries, Iceland, Liechtenstein, Norway, and Switzerland ask for the "Freizügigkeitsbescheinigung", when they register at the Bürgeramt.