I'm planning to go Harbin fr 29/12/15 - 1/1/2016. Can someone pls advise what to do n where 2 stay

Winter is the best season to go to this place. You can visit the Grand World of Snow, one of the must see places, St. Sophia Church, Sun Island, the Centre Street, etc. If you are interested in skiing, Yabuli Ski Resort is a good place you can not miss. As for the accommodation, you may consider staying near Centre Street in city center area.