Be there when you are building is my advice.
If you can't be there for the whole construction make sure you hire someone to oversee the project for you. Do not leave it to your contractor.
There are many good contractors here on the island, shop around and get as many estimates as you can. Ask for references, don't be afraid to ask them to show you work that they have done.
Also make sure your plans are submitted as early as possible so that any changes that have to made will not delay the construction.
Any thing I can do to help just ask