Alaska Cruise

Looking for advice or comments regarding the San Francisco to Alaska round trip cruise. We are planning a cruise to Alaska in July of 2005 and would like to know what others have to say about it and any recomendations for it. such as, which staterooms w/balcony are best?. What costs are usually not included in the cruise price? and what is the protocol for tipping and service?
any comments and advise would be greatly appreciated

Thanks...Dave