DNA is a useful tool to support traditional family research. It gives a broader view of the family ‘s history and may provide some surprises along the way. The Family Tree should be as detailed as possible . The descendants (all of them!) of your Great Grandparents are particularly important, since identifying these people will help when you connect with your DNA matches. A short presentation I gave at GGI 2017 Conference below.
FACEBOOK is an excellent meeting point for DNA researchers on every level! Find my group for Cork DNA here
ISOGG International Society of Genetic Genealogists‘ free Wiki website answers most questions.
YOU TUBE has free presentations from DNA Conferences worldwide. Start with Genetic Genealogy Ireland .