If you already know your patriot, the first step is to look him or her up in the NSDAR database, the Genealogical Research System (GRS). You can access the database from the DAR website. You can also search by member or descendant if you know the name of a relative who may have been in the DAR.
If you live in the District of Columbia area, the NSDAR has a large genealogy library that is free and open to the public Monday through Saturday. It is a great place to start your research and we are happy to meet you there to work with you, just send us a note!