Can I use an unlocked iPhone from Canada in Germany?

I'm going to Germany for a year in September and I was wondering what to do about a cell phone?
I heard I can use an unlocked phone there but I just didn't know if the SIM card slot is different or anything.
I would much rather have a prepaid type of thing going on as I'll only be there for 11 months to be exact and would not like to have a contract.
If anyone can help me out with details and maybe even some rates over in Germany, that would be great!
If it changes anything, I'll be living in Bielefeld.

As long as the phone is unlocked, you can use it anywhere with any SIM card. MicroSIM and NanoSIM are available in Germany.