JimbosJet.
As previously said the best thing would of course be to "communicate" as much as you can with Norwegian people. I believe there aren't any real shortcuts. I'm a swede living in Norway at the moment, working as a dispatcher for Norwegian and even I, though not that often, have issues with the Norwegian language. I would say that Norwegian and Swedish are as different as Texas-amercian-english and Scottish.
I think that tutorial cd's, grammar books etc. would give you the same progress in one year as one month IN Norway with the Mrs would .
My advice would be to communicate as much as you can in Norwegian with your lady, try to watch a few norwegian movies per week and try to visit the parents in law as often as you can.
Just speak try to speak it and soon you'll get the hang of it.
Good luck mate!