All the major cruise lines offer Alaskan cruises, and there a number of smaller ship companies that specialize in the region. The following links will take you directly to their web sites so you can find their latest specials and promotions.
There are a few spots where people congregate to talk about cruising. A select few have a good, regular group of participants that are always happy to give you the benefit of their thoughts and experience. The following are my short list of favorites.
Alaska Forum at Virtual Tourist