Norway/Sweden in May. First time Europe.

Hello Andrew. You will be at Europe a total of 6 whole days. Therefore, I recommend : be at Norway, only. When you do the Norway in a nutshell trip, have your overnight acomodation at Aurland (the first place the boat stops at after Flam). I do not recommend traveling in any night trains. You might like to visit Lillehammer and Trondheim.
I traveled across Norway in May, 2007. Norway is a tranquil country, and the people in Norway are wonderful. And they talk in the English language.

Your main problem is that your base is Oslo and you want to go both west (Bergen) and east (Stockholm), putting you in Oslo at least briefly, three times in 6 days. That's logistically too inefficient for my tastes. You could cut out Stockholm all together and travel at a slower pace between Oslo and Bergen. That would be the obvious solution. But Stockholm is a stunningly beautiful city and there is a particular youth hostel there across the water from the old part of town that is a wonderful experience (PM me for specifics if you are interested). So another option is to do the "nutshell" as a day trip from Oslo. It's a really long day, and you would have to miss Bergen to do it, but you would see everything else on the nutshell route worth seeing. So basically, the time spent could be around three days each in Oslo and Stockholm with some day trips. Missing Bergen would be a drawback, but Stockholm is much more interesting than Bergen! This plan also negates the need for any rail pass. Look into regional flights on SAS airlines before you commit to rail. They have some good deals. There is also a bus service that is likely the cheapest option. It's something to consider...

You might look into getting a flight on Sunday morning from Bergen to Stockholm. Stockholm is a strikingly beautiful city, but I really like Bergen too.

Thanks for the suggestions. I think I am going to look into flights. At least do a flight from Stockholm to Oslo so I don't have to take a train back to Oslo to just catch a flight. I'll also look at the flight from Bergen to Stockholm. Is there something wrong with the night train from Bergen to stockholm via oslo? I was considering it becuase rick mentioned it in his book.

There's nothing wrong with trains in Scandinavia. In fact, they are clean and efficient. However, flying is usually much faster and much cheaper. Additionally, I don't think there's really a night train between Bergen and Stockholm. There's a train from Bergen to Oslo. And there have been, on and off, trains from Oslo to Stockholm. But I don't know of any unified train experience on that route. The reason I said trains were on and off from Oslo to Stockholm is because it's a very unprofitable route because it takes 7 hours while a flight takes around 1.

Doesn't look like you have a hell of a lot of time in Oslo or Stockholm, so def get Rick's Scandinavia guidebook, which will be super helpful for the "must-sees" in both cities. My personal reccomenidations; in Stockholm, make sure to go to the Vasa Museum; awesome! And def stroll around the Gamla Stan (old town) and go to the town hall. Gorgeous mossaics inside and from the tower outside, you get a great view of the city. In Oslo, don't miss the Viking Museum, Kon Tikki/Thor Hyerdal Museum, and the Munsch museum (I know, that's a lot of museums for 1 day, but they're all great!). Other great Oslo museums are the Maritime Museum and the Norwegian Resistance Museum (you walk away LOVING the Norwegians; they were incredibly anti-facscist and saved many of their Jewish residents in WWII) but you won't have time for all of these. If I had to pick, say 2, I'd PROB go w/ the Viking and Munsch. And def give youself time to spend in Frogner Park, and, specifically, within the Vigeland Sculpure Park; pretty amazing stuff. With someone like you, with relatively little time in these 2 great cities, Rick's planned itinnerraries should help a great deal. BTW, you'll love Norway in a Nutshell; 1 of my personal favorite European experiences ever. It's an incredible day, from the train, to the waterfalls you pass (and stop at for pics), to Myrdahl, to the highlight; the boat through the fjords; ALL makes for a day you'll never forget. In Bergen, give youself time to take the funicular up; affords fantastic views of the city, and from up-to, there are many hiking/walking opportunities. Wow, all of this writing re: Norway abd Sweden make me want to go back now! You're off to a spectacular region of Europe; have a blast!

Andrew, thought of something else in Oslo that I loved, but not sure if you have time for. The Homenkollen (my spelling may be WAY off there!) Ski Jump and Ski Museum. From up on top of the jump, you get an awesome view of Oslo below. A tram takes you there from the city center (it's explained in Rick's book); I remember it being super easy to get there. It's a nice way to get out of the city center a bit, IF you have the time, of course.