"If you have questions regarding your rental contract, problems with your landlord, need legal advice, etc. - that's the place to go. You have to become a member (85CHF first year) in order to get a free consultation (they have walk-in hours every day, though get there at least 30 min in advance).
The person we spoke to was professional, spoke very good English and gave us clear explanations and what seems to be a good advice."