Andrew T.
Yelp
This place is so large as to be daunting. so many little paths between so many little buildings! I think I heard as many as 130 or 150? Either way, there's a lot to see. There are permanent indoor exhibits on Sami culture, Norwegian church and clergy, and other things, in addition to all the other buildings, such as the stave church, the collection of farm buildings, and even an apartment block showing different model living spaces for varying groups of Norwegians.
The Sami culture exhibit was good for me - I knew of the Sami, but knew nothing about them, and probably would have incorrectly referred to them as Laplanders or Lapps, which it seems is incorrect. So even this ignorant American can learn a few things. Also, I don't know if this is just a weekend thing, but there were a number of costumed reenactors, like the farmer's wife and the farmer, happily answering the questions of the fascinated little kids running around the place. There was even some livestock, allowing me to unexpectedly fulfill the quest I had been given to photograph livestock, even though I was in Oslo.
A better map would be good - something in a larger scale. Since the museum grounds are large and the little paths are many, that would be helpful. However, there are pretty frequent signs throughout the grounds directing you to the major sights as well as back toward the entrance This museum is a little on the expensive side, but it's also pretty vast. I had to make myself hurry through a bit, since I was planning to do several other things the same day. Just know that you can spend a lot of time here, so that helps to make up for the high admission price. And it is free with the Oslo Pass - a full fifth of the price of the card gets paid for if you go!