Just finished a cruise on the Sun - so this should be up to date:
tips - $10.00 per day added to your statement
pop - $1.50 per can + 15% tip
Pop card - unlimited pop $28.75
Internet - $3.95 per email - be careful there is an admin fee the first time you use it - other packages will be available on board
Yoga classes - $5.00 but workout gym is free
All liquor will have a 15% tip added - be careful it also has a place on the bill to add a tip - this caused some confusion with the older cruisers on my cruise as they didn't realize that one was already added.
Hope this further helps you and enjoy your cruise to alaska.