GEDmatch, a DNA tools site, was originally created to compare GEDCOMs, a function you can still use it for. A GEDCOM is a plain text file of your family tree formatted so that any genealogy program can understand it. Click here for the wikipedia entry explaining this in more detail.
In my talk I emphasized that it is best to upload a privatized GEDCOM with no more than 10 generations of ancestors then connect it to the DNA test for that person. This will help you use the relative matching tools. I promised in the presentation to explain how to create a GEDCOM. So here are a few of the many ways.