Bring a long coat and the Goretex. Not known as the windy city for nothing. Excellent transport links. A car is a waste of money if not for lifestyle. Live in Gdansk if young, Gdynia if older, Sopot if rich/daft.
What sort of accomodation? Depends what you like. Try to get a flat with a sea view. Otherwise, what is the point of living here? If monied, condos in Gdansk Jelitkowo or Brzezno if you like the coast I guess....Wrzeszcz or the Old Town if you like older type buildings....or the other side of the ring road if you like forest and countryside (then you need a car....)
My experience? Gdansk is great in summer, tedious in winter.