You will likely have to employ a variety of methods to eliminate a tobacco odor problem. To start with, make sure the home is well ventilated by leaving windows and doors open for as long as possible. You will also want to use odor absorber's placed around the home, be sure these absorb the odor and not just mask it with another smell. Baking soda, citrus peel and coffee grounds are all good natural odor absorber's. Replace HVAC or air conditioning unit filters.
There may be some items left behind by the previous owner that you want to keep. Blinds are usually one such item. Take them all down and soak in a tub of soapy water, then give them a scrub and hang to dry out. When cleaning hard surfaces, use a detergent that contains ammonia which is good for removing nicotine (not good for wooden surfaces though). It is advisable to replace all the bulbs in the home, this is because when turned on, they will warm up and any nicotine residue on them will diffuse a bad odor into the room. You could also try cleaning them.
It may just be better to replace some items in the home. Carpets are a good example of this as it is very hard to remove nicotine from them. Before you install a new carpet, however, its important the flooring underneath has been thoroughly cleaned and dried out. Before painting a wall, ask for advice on which paint is best to use as very often you will see nicotine start to seep through the paint.
Following these tips should help you be well on your way to a fresh smelling home in no time.