The first thing is to get to see those 2 aunts. While this may be awkward if you have had no communication with them up until now sometimes this desire to hunt up our roots can be a bridge between people who have not spoken often. All they can do is say no and then you are no furthur ahead. The oral history is where you have to start. Most genealogical primers or guides will help you. As you are a Tierney you may will eventually be back in Irish records. If you get back to ancestors that came from Ireland email me and I will tell you where to go first. I am at this point doing my research of my wife's family there and it is becoming easier with this information age.There are many sites out there with general information about how to start. My favourite book is Tracing your roots by Angus Baxter as I met him in Lakefield where I grew up and had started researching just as the 1st edition of his book came out (1984) I was somewhat fortunate to have started over 20 years ago while still in highschool and the research brought me around to many of my grandfathers sisters and brothers whom I had never met before. If you want a list of oral history questions that help get to the important items email me and I can send them to you directly. My wife's ancestor Patrick McCarthy married Catherine Tierney (sister of Matthew Tierney) in 1835 in Ireland. She was born in Limerick c 1812. Let me know if you got over to see those reletives and how it went.