Welcome aboard.
First there are two types of cruises that a readily available from mainstream lines.
Week (7 nights) return from either Vancouver or Seattle
Week (7nights) one way to Seward from Vancouver or visa versa.
Both cruises will general stop in Ketchikan/Juneau/ and one other port plus a glacier.
The one way cruises general stop somewhere else also.
One ways are a bit more relaxed I have heard. Out of Vancouver is my choice cause I am bias. But if you do go out of Seattle you spend a lot more time in the open Ocean rather than the quiet waters inside.
Certain lines have Glacier Bay on their schedule. HAL & Princess for example
Certain Lines have Hubbard // RCL & Celebrity....
There are others also but that's just off the top of my head.
The grandaddy of all tours is of course one by one of the main lines for a week prior to or after a one way cruise. I suggest the Tour first and a rest on the ship. I have no tour experience as living in Northern BC we were into the area further north a bit anyways.
Other ports available Sitka, Icy Straight Point, Skagway and there are more bays and glaciers spread out between the lines.
There are day trips of course in all the Ports and all the towns have the usual "Tourista" shops. Whale Watching is a must and all sorts of plane trips and smaller vessels are available also.
I recommend that you kinda decide exactly what are must see's for you and based on your budget (air cost's one way are more) pick a ship. Flying into YVR can be more also but you can get here (Vancouver) via Seattle easily with transfers/train or bus.
based on your thoughts on all of that I'm sure we could make specific suggestions.
There are also smaller ships and some longer cruises out of San Fran and early and late in the season cruises will come North from California and do Alaska and then return to the Home Port for the summer. Visa Versa in the Fall.
Nuff for now!!! ? get back to us. 
