First time cruisers - what to expect?

[Barney]

Though old-timers (65), Betty and I will be first-time cruisers in a couple of weeks (Dec 15-24, 2005): 9 nights aboard Century (Celebrity) to the Western Caribbean, out of Ft. Lauderdale, with stops in George Town, Grand Cayman (tendered); Ocho Rios, Jamaica (docked); Oranjestad, Aruba (docked) & Willemstad, Curacao (docked). We are looking for tips about what to do (or expect) & what not to do (or expect) aboard the Century & especially about what to do (or expect) & what not to do (or expect) in these ports. Any advice about any of the optional port excursions? (Nothing too strenuous; we've got some disability issues.) We saw one online description of Ocho Rios as a "cesspool" --accurate? We will be very grateful for any suggestions or information. Thanks! --Barney