M.J.
We're also going on an Alaskan cruise, but in July. Check out the website www.cruisecritic.com. The boards there will give you super tips on the best sights to see and how to get the most out of your cruise. I've been on a couple of cruises and highly recommend a room with a window. There are times you'll want to just come back to your room to relax and it's great to have the sunlight and view. On our last cruise, we sat our on our balcony and relaxed as the ship left port and it was wonderful. Not sure that we'll get a balcony this time, given that it's likely to be cold up there, but will at least get a window.
Have fun!