2 ways to hear about this island to the north. 1 is to talk to a guard about latest rumours. If it doesn't work, talk to several. He'll mutter something about his son being sent to Fort Frostmouth, and Daddy thought that he brought his son up well, but obviously he failed at something. If that doesn't bring up a response, you may not have the GOTY edition. The second way will instantly tell you if you have it, and if the first way fails, you should try this way before writing off the first. I only talk about the first method first because unless you are in Ald'Ruhn its eaisier to do.
Outside the Ald'Ruhn mages guild is an old man with very little brainpower. He's just standing there, about a foot south of the main door. He's been placed in the game as part of Solstheim.
After either (or both) of these two methods have been done, you can ask anyone about 'Solshiem' (even totally obscure characters in the middle of the wilderness). I believe Vivec and Almalexia won't talk about it. Everyone else will. They'll whine about it being 'terrible' and then tell you that there's a boat from Khull. Go there, and find an Arognian informing you that he is ready to captain the 'last boat to Solstheim'. He can take you there.
Its a lot of fun, and a lot better than Tribunal in my opinion. Raven Rock is a fantastic distraction, and I found myself resting next to Falco until the next quest became avaliable.
If pro is the opposite of con, is Congress the opposite of progress? - Thanks to Blake for the avatar!