Book Resources Available Online for Puerto Rico
So far ninety-nine percent of the posts I have made, they have been free resources. Most of those that do cost, usually pertain to books recommended for purchasing, if available or advising you to check your local library.
However, there are times that I will recommend something that costs, like the Sociedad Puertorriqueña de Genealogia. Well this time, this resource is a monthly membership of $8.99 but to over one million books. Within their collection, they have many books on Puerto Rico that will assist you in your research, take a look and it may benefit you.