One of the things I forgot to mention, any links I provide will always open in a new window. The same goes for the AGN so make sure you turn off pop up blockers for both websites.
If you're looking for Part 1, then click here and it will open in a new window.
So below is the search window. Notice there are two tabs, for beginners stick with the Simple tab which is the default and the Avanzada is of course for Advance searches. The advance search is where I recommend that don't use until you get used to the website; especially if you're not familiar with AND/OR use. You can gain more information and narrow down your search which I will provide an example for those who want to try advance search.
So for my example I want to know more about the History of Monte Cristi. Here is where it is very important that you use a translator, especially if you don't know how to speak, write, or read in Spanish. Remember everything on this website must be searched in Spanish. As you can see I typed in "Historia de Montecrisi"
Click on "Buscar" and the next view is the search results. So let's look at the search results here. You have a few options available. Anterior is to go back to the prior page however you can't go back to tweak your search. Another is Siguiente to go to the next page if you have that many searches and the last is Nueva busqueda which provides you the ability to start a new search.
Now notice I've circle one of the search results in yellow. If you click on the link, it will open a popup window and it will provide you details. You can even reserve the microfilm to view if you have a user account; only those on the island have these unless you want to call the archive and ask if you can have one. Note that those of us not on the island will have to reserve it once you arrive there. However jot down the information so you'll have it when you get there. It will save you a lot of time in your research.
Now to narrow down your search and using the same search but adding additional information. It's very simple and they even provide a little blurb about how to use AND/OR. I used AND so that I get exact search on anything doing with the history and architecture of the city as shown below. Notice how the search results has been narrowed down to exactly what you're searching for.
I hope this walk through helps someone along the way in researching their Dominican ancestry.