There's lots to see and do in Vancouver. There is a "Vancouver FAQ" thread started in the main cruise forum. I'm going to start one for Victoria once I get back from visiting DL and catch up on work.
Quick answer - Science World, Vancouver Aquarium, Grouse Mountain, Capilano Suspension Bridge, Stanley Park and Granville Island. Google any of these and they'll come up with websites. These are top attractions - there are many more lower key ones.
The Port is right downtown - several hotels in walking distance or a very short cab ride. The ones right at the Port literally are high class - really expensive ($300-$400 a night - if not more). There are a few hotel chains in the area, but exactally where I'd need to do some research. Plenty of shopping and restaurants close by. Very good Skytrain (like a subway) system available if you want to go further out to Burnaby, Surrey, and Richmond.