Durga pooja is the 9 days festival as you said celebrated in Bengal.
It is also celebrated in south Inida speacially Mysore in karnataka as dasara or the world famous mysore dasara. This grand celebrations in the state came into practice from the wodeyars of mysore who are the great worshippers of godess chamundeshwari. It is celebrated as the festivel of lights for nine days throughout karnataka, in Mysore for nine days you can watch the brightly lit roads, shops and of course a welcoming chamundi hills. In city palace for nine days world famous musicians give free concernts. Dasara or Durga pooja or Navarathri as it is called is an opportunity to worship godesses durgae in nine forms: first 3 days as Durgae or parvathi(for strength and courage), next three days as saraswathi(for knowledge and wisdom) last three days as lakshmi(for wealth and well being). It is believed that Duraga killed Mahishasura on the last day of navarathri which is grandly celebrated in south india as Vijayadashami (victory over evil). It is strongly believed that whatever new ventures you undertake on this auspicious day it will become success. Tomorrow is that day, wish you all sucess for today and tomorrow, I remain,