Lonnie, start with what the ship has to offer, that will give you a good overview of what each island has to offer.
St.Thomas - known for its beaches and shopping. Go to www.vinow.com for information on beaches. Check out Paradise Point - grab the tram - short walk from Havensight Pier - this is a picturesque place- you get a gret view of the harbor, there are restaurants, shops, a beautiful Botanical garden to explore - alot of weddings take place here. You can spend a couple of hours or all day here depending upon what you do.
San Juan - take a ships tour into the rainforest - its amazing. Or just wander around Old San Juan and Fort ElMorro for a few hours
Went to Tortola for the first time in Dec and decided not to do a ships tour. Right at the dock you can get an open air taxi for a tour for less than the ships tours and it was great. The driver takes you to great places for photo ops. When tour is over you can get off in town and have time to do some shoppping. We even had 45 min at one of the beaches, so either wear or take you bathing suit.
If you are in San Juan during the day you can take the ships tour to the rain forest (it was beautiful) and still should have time to walk around in Old San Juan.
Star Princess 2005, Sun Princess 2005
Caribbean Princess 2006, MSC Lirica 2006 , NCL Pearl 2007, Majesty of the Seas 2008, Carnival Destiny 2008, MSC Lirica 2009, Carnival Valor 2009,Carnival Legend 2010, Carnival Liberty 2010,Carnival Fantsay 2011,Carnival Valor Feb 2012, MSC Poesia Dec 2012, MSC Poesia April 2013