Accommodation questions

Hello , good day !,My name is sarat and I will be commencing masters degree course in Audencia School of Management, Nantes
starting January 2013. However before I apply for student Visa I need to have booked accommodation
for minimum of 3 months from the date of my arrival.I understand that a guarantor is needed to rent a place. How do i do it if i dont have a guarantor in France and can only open bank account once I personally come there.Also CROUS accommodation is not possible as it should be applied betwee january - april.

please clarify me how does one get accommodation booked without a known person in france as guarantor and what other way is there is book a place to stay.

Thanks,
Sarat