Donna, I posted a review of the trip on Cruisemates last summer; it is still there. While there are certain things about cruising that are getting old -- the baked Alaska thing and the shows --, we enjoyed the Infinity very much. The thalassotherapy pool is great -- go on the first day before others discover it. Later it gets too noisy to hear the new age music that is piped in. For the rest, enjoy the scenery. We didn't have a balcony and so had to use public venues. The Constellation lounge on the top deck is a great place to sit during the day; it only gets crowded for the Hubbard Glacier when it is the premier spot to be. There are some comfortable chairs on the Plaza deck, tucked behind the elevators, that afford a close up look at the sea. We saw orcas from there one evening.
I remember the library being well-stocked, but then I enjoy reading and looking out at the sea. The first full day is a sea-day. There are some spectacular views around midday in the Inside Passage. A great place to go is the open deck above the Constellation Lounge; you can stand on a table to get above the glass windscreen and pretend you are Leonardo de Caprio.