From Copenhagen there is a direct train to Stockholm called the X2000. X2000 trains go throughout the whole country and are high speed train. They offer nice views of the country, so make sure when you book a seat on the train you have one with a nice view!
pic taken from: http://www.railway-technology.com/projects/sweden/
I had a Eurail pass which came in very handy through Sweden because the trains are relatively expensive here.. A ticket from Copenhagen to Stockholm costs about $65 US dollars... just make sure not to smoke on the trains.. it's illegal throughout Sweden...
The first time I went to Stockholm, it was by bus and I came from Halmstad. That was ok, the trip lasted one day
The second time I went by train from Alkmaar, where I live (30 minutes from Amsterdam). This trip was quite alright. I was alone, which was no problem as I like to travel alone. It's just that the trainservices in Holland suck so I missed the train to Amsterdam, which make me miss the first train to germany aaaaargh!
Technically, it is possible to get from Amsterdam to Stockholm in one day. The trip is: Amsterdam-Ösnabruck, Ösnabruck-Hamburg, Hamburg-Copenhagen, Copenhagen-Stockholm. It will take a whole day, but travelling by train is lovely in Germany, Danmark and Sweden when you're used to the Dutch railway company!
GOOD TIP to plan your trip, if you leave from Europe and go somewhere in Europ: www.bahn.de! The German Railroad website is abolutely the best.
Most people will arrive in Stockholm either at one of the airports (most visited is Arlanda) or at T-centralen, the centrail train- and subway terminal. From the Airports you can take the Flybus (Flygbuss) to T-centralen easily.
At T-centralen, go to the information desk (99% of the people there speak English!) and get a map of the subway, and a free map of the sity. The subway was my favourite transport in this city. With the map of the subway, you can easily plan your trips. You can buy a card for the subway for a whole day and travel around the city with that.
A joke that I did was while arriving in Stockholm, after 24 hours of train from Geneva..........and a friend was sleeping..........So I took all my luggages out of the train in Stockholm.....I convinced a friend to do the same........and the train was empty because we had arrived in Stockholm!!!!!!!!! And I asked the controller to say to my sleeping friend that the train was goin to another city.......and he saw us outside the train when he waked up!!!!!!!!!!!!!!!!!!!! SURPRISE!!!!!!!!!! He was moving around and around to take is luggages which were in different places,,,.....and outside...I was saying to him: Bye! Bye!!!!!!!!!!!!....................And taking a picture of him ...lol
TRAINIn this beautiful 18th century environment modern transportation vehicles doesn't really fit, but is neccessary
These are pictures of the new shuttle trains in Stockholm. They go to/from the suburbs to/from Stockholm City. They are new and modern.
Definitely by Train. Experience the unique experience in being inside of the train which is also inside of the big boat!
[I like the design of the roof of this building!]