Hey there!!
I rarely check the families section, but I'm glad I did! My fiance and I inherited my grandmother's house this spring. It's a wonderful house and I was glad that a home that's been in my family for YEARS was now going to be our first home together. The draw back? My grandparents smoked in the house for over 30 years and they were NOT light smokers. Everyone in my family also smokes and any gathering at g-ma's and g-pa's had smokers all over the house. Over the last few years, my grandma got so ill that she didn't clean her house anymore-she just smoked and smoked. I'm talking nicotine EVERYWHERE. Walls, wood work, floors, etc. What we used was trisodium phosphate (TSP) to get it off of the walls before painting them. It worked wonders. We followed with Kills primer and then paint. All is well now in our beautiful home.
The TSP comes in several different forms, I started using the boxed powder that you mix with water but that got to be a pain in the butt. When that ran out, I got a concentrated spray that you spray, leave for a minute, and wipe off. It worked so much better than the other stuff. Be advised though that it is pretty strong and fumy, so do it without the little ones around...same goes for oil based primer-it is VERY strong smelling, so make sure the room is ventilated and the kids are not around.
If you are still concerned, you can always call a disaster cleaning service and they will professionally clean everything (they use TSP). Even though they normally clean fire smoke damage in houses, they also have the capabilities to clean cigarette smoke damage. We were going to do that before we decided to just tackle grandma's house ourselves. We got a couple of estimates for the smoke damage cleaning services to do some rooms, some walls in a few rooms, floors in others, etc. It wasn't too bad in price, but we were talked into doing the work ourselves and it wasn't too difficult.
Hope this helps, good luck to you!!