Using the negative in Norwegian is usually quite straightforward, you put it after the verb in main phrases.
When you read a lot of Norwegian you will, however, see that location changes sometimes. The whole list of rules is quite extensive. I have tried to make an overview in a Two part series - Part 1 - Part 2.
Following the 5 rules in those to parts will help you getting the placement right in more than 90% of the cases.
It should be noted that getting the placement wrong will not make you misunderstood. That being said, it is an error that really is easy to spot for a native Norwegian speaker.