Decide which port to depart from. Most cruises through Puget Sound and to Alaska begin in either Seattle, WA or Vancouver, BC. Seattle is further south, so most cruises originating there also make a stop in Vancouver along the way.
Plan the length of your cruise. Traveling from Puget Sound to Alaska is not a short trip, so most Alaska cruises are at least six to seven days for a one-way trip. Many cruises, especially those that are round-trip, are considerably longer. 10 to 14 days would be standard for a round-trip.
Pick a cruise line. While all major cruise ships have similar basic amenities, each company offers slightly different service while on board. Research the various cruise companies to determine which service is right for you. Celebrity, Holland America, Carnival, Princess and many other companies all offer trips to Alaska.
Pack and plan for your trip. During the summer, the Pacific Northwest is generally warm and dry, although you should not expect extremely hot temperatures at any time. Multilayered clothing is best for outdoor activities. If there are specific on-board or shore activities that you are especially interested in, book those in advance since many sell out by cruise time.
Arrange for transportation to and from the cruise. If you are taking a one-way cruise, you will need transportation into and out of different cities. In order to allow for travel delays, make sure that you arrive well before your cruise departure time and that you depart several hours after your ship docks.