You can also use sites like this one to help you plan your trip
Santo Domingo - vistor information, Custom Travel Itineraries, Virtual Concierge, Trip Planner, Dream Trips, Family Time Travel
I know there are many sites but I generally recommend this one just because most of the photos for Santo Domingo are mine. :laugh:
Another bit of advice even though you didn't ask - don't worry too much about being a woman alone - you only need to worry enough to stay alert to your surroundings and not to be silly about things like traveling with a person you just met to "see something you would like, it is just inside here, or down this alley" etc. if they are trying to lead you off to lonely secluded area. Don't flash a lot of expensive jewelry or cameras. So in other words don't do anything in Santo Domingo that you wouldn't do in New York, London or any other large or small city in the world. The cities of the DR aren't any more dangerous than any other place if basic common sense is used.
Since you are traveling alone DON'T go and get really drunk at the clubs with your new "best friends". Sure go drink, laugh, dance and have a good time but remember to stay in control because you don't really have anyone there that you KNOW has your best interests in mind and this applies to both the locals and other tourists that you meet - you don't really know them, you've just met them and weirdos and bad people go on vacation just like other people. Enough Presidente or Brugal to have fun but not enough to effect your judgement is the rule to follow especially when traveling alone.
I know you didn't ask about safety and I don't mean to imply that you aren't smart about safety but I know as a woman who also often travels alone that it never hurts to hear a reminder.
Have a great trip I am sure you will enjoy it!