Can you give me tips on a good Alaskan cruise?

cruise
danaluana asked:

I want to take my 87 year old mother on an Alaskan cruise around June or July of 2007. She has voiced a desire to see Alaska. Can you tell me the best, yet economical, cruise line and the best time to book, early or last minute. I’ve never been on a cruise and would appreciate any advise available. Thanks.