When leasing an apartment what is required with regards to permits or other papers? Is it sufficient to have a letter from your employeer stating that you are working in Zug and also showing your passport?

bumping this for SteveSP - I need to know this too...

i.e. what are the absolute necessities, and what are the nice to haves?

have seen on here mention of a document proving you have no Swiss debts - do you still need this if you have only just emigrated and this is your first job/apartment in CH?