If all you have is a week, I suggest picking just a few places. The whole country is fantastic (in my very biased opinion) and anywhere you pick will have oportunities for wandering around un-crowded towns and hiking in beautiful scenery.

The flight from Oslo to Trondheim takes 50 minutes, but remember you also have to add in the trip to and from the airports (both airports are quite a ways outside town) and getting to the airport an hour early for check-in. And flights in Norway can be very expensive. The train from Oslo city centre to Trondheim city centre takes 6-7 hours (depending on the train you take) and takes you through great scenery over the mountains.

If you spin and weave, the sheep farm would be a great place for you to stop. They now specialize in merino wool and do sell their own yarn, all in natural shades from white to black. The wife of the old farmer (she sadly passed away a few years ago) was a keep weaver as well and several of her works are hanging up around their house.

Read up on things and look at pictures on the internet and when the time nears, let me know what you decide and I'll be happy to help sort out the details.