Hej Stig Arne from a fellow Scandinavian

I'm from Denmark and have visited your beautiful country a few times during the last year and a half. With almost the same gear that you have. Remember good pictures is not all about the gear, and while a pro setup would be nice to have, a d3100 is really a capable camera. I can tell from the pictures I have from when I first got my camera and till my most resent trip to the Stavanger-Lysefjorden area, just about a year later and the biggest part of a 365-project later, my pictures had improved a lot. So my advise is to shoot, shoot and shoot (and maybe read a bit about how others are doing).
From your pictures it looks like you are already well on your way
Happy shooting