Congrats on your Masters degree. You might find some useful information on finding work in Norway on these pages: Working in Oslo and Working in Norway.
Having studied in Oslo, are you able to speak Norwegian? How fluently? Generally it's quite hard to find work in Norway without being very competent in the language. Then again, this might not be as applicable if you're planning on teaching English, for example, but even then Norway doesn't have as big a market for English teachers as some other non-English speaking countries do (China being a good example of one that does).
Perhaps you could speak to any lecturers or professors you might have had contact with during the course of your studies. They may have useful contacts or at least be able to point you in the right direction.
Best of luck