Hello Donalee,
Me and my husband just got back from a Carnival Victory cruise on 09/22/02 (it was our first cruise). We stayed at the Embassy Suites hotel about 20min away from the port of Miami. The address is 3974 NW South River Drive, Miami, FL 33142, the Ph# is 1-305-634-5000. We got a special rate from our travel agent and it cost us $109/night (we only stayed one night). I know they have the free shuttle service but I'm not sure if they will take you to the port of Miami because we had a rental car (I listed the ph# so you could call if you like). It's a really nice hotel. Free complementary breakfast (and I'm not talking about cereal either...the works!), free alcoholic beverages from 5 - 7pm, etc.
Is this your first cruise? If so, I have loads of info for you. I even have an arial shot of the port of Miami, although it makes it look so much simpler than the caos you go through when you're driving through it.

) If you have any questions, just let me know.