I used the RS book as well as Trip Advisor. If you are going in summer season the Rick- suggested English guided tour of the small historic area was excellent. As well, it provided an overview of the museums and the opportunity to re- enter them later. Depending how much of a history buff you are, you could easily spend a couple hours after the tour. I was there in July and walked down from the funicular after admiring the view. Again, assuming summer visit, you could do that later in the evening. I also went to the Kode Museum(s) to see the Munch and Kittelsen. I believe you can take tours by boat of varying lengths. For me 1 and 1/2 days was just right. Travel is subjective, be sure to do your own research! For example, I have no interest in restaurants!