Done 2 Princess Cruises to Alaska.
Somewhere there are posts about tours, but, let me tell you the ones I highly recommend.
Juneau - Mendenhall Glacier Helicopter Ride & Walk About. This was awesome. To actually get out & be able to walk on the glacier was great. They have more active glacier tours, but, this was fine for me. Be sure to dress in layers & warmly, as it can be quite cold on top.
The tram downtown is good to get great pictures. If you have a clear day.
Be sure to save time for a stop at the Red Dog Saloon.
Skagway - White Rail Pass train ride is excellent. Again, save time to wander downtown.
Good shops & taverns for an Alaskan Amber.
Ketchikan - Misty Fjords Seaplane Ride was excellent. I love to walk around & shop here too.
I have not personally done the whale watching or nature tours. However, friends have done them enjoyed it. Also if you enjoy fishing they also do some great expeditions.
Hope this helps. I typically am a sun person, but, really enjoyed the splendor & beauty of Alaska. Glacier Bay is just magnificent.
I prefer Glacier Bay to Tracey Arm, based on my cruises.
What ship are you going on??