Here is a robust article that is at the same time very personal, accessible, and in my opinion, not all that intimidating, considering the depth of the subject:
by V. Rev. Antony Hughes, M.Div; St. Mary Antiochian Orthodox Church, Cambridge, Massachusetts
Also: Original and Ancestral Sin: A Brief Comparison by Alison Bennett
picture from Fr. Ted’s Blog: John Romanides THE ANCESTRAL SIN (B) see also John Romanides THE ANCESTRAL SIN (A)
So if the first article seems too difficult, try the second. And if you want to go somewhat deeper, read what John Romanides says on the subject.