Our cruise company was Princess. You can book the ticket from Princess.com. They have multiple packages. The one we chose was the 12 day-cruise pachage, starting from Vacouver and ending in Anchorage. The ship name was Star Pincess, seven days on board and five days traveling in Denali. Everything covered for about 2-3 k US dollars (not including excursion fees). The best time for Alaska should be from June - August. Our trip was from June 13-25. Of course, no one knows the weather condition.
There are so many excursion activities to choose. We took 1) "Best of Juneau" (in Juneau). You can watch whales (we have been told that July to August are the best for whale bubble net feeding) and Mendenhall glacier. 2) "Alaska Nature & Wildlife expedition" (in Skagway - Haines) to see eagles and beautiful inland landscape).
Hope this help.