Beautiful city. Will be cold and probably snowy. Actually cheap in Nordic terms, but for us it is scary expensive! Great city to walk..assuming that you have the right clothes. Fantastic levels of English.
Went in January about 10 years ago (before Ryanair started charging for hold luggage). We stayed in a B&B run by Stockholmers and asked them where to visit, eat and drink and we found it quite reasonable, like most big cities go where the tourists go and you might as well walk in with your trousers round your ankles.
I used to be there once a month for work, its a beautiful city. remember after doing a full days work i was taken for a city walk by my local and blimey, there is a lot to see!! take some walking shoes, my leather soled work shoes were far from ideal!!
As everyone has pointed out, Stockholm and Sweden in general is pretty expensive. There is an Irish bar in the city center, normally i wouldnt advocate visiting an irish bar anywhere other than ireland, however i know the head chef, and its a pretty awesome and less expensive night out in there!! will try and remember what its called!
Hello from Stockholm,, we are off to Oxford tomorrow for visiting our daughter for a couple of days....What to do in Stockholm this time of year.. There is a filmfestival in the kulturhuset at the city center.