EFA has collected numerous resources to explain the concepts and tools of Y-DNA analysis for genealogy.
Haplogroups, Haplotypes ... for the Flustered
Y-DNA Project Articles - 20 articles, published 2005-2009; Status Report, 2011. These articles lay out the case for the Y-DNA project as a way to understand the relationships among Ewing men. Y-DNA clarifies relationships that are often more ancient than our conventional genealogies can show.
Related Articles and Books
Colson: A Brittonic Y-DNA Cluster
Ewing, David Neal: Chancellor's Message
Ewing, Eddie L.: Using Y-DNA Testing to Prove a Relationship
Ewing, Thor: Who Were the Ewings?
Gilbert: Oscar Ewing and His DNA Odyssey
Hodges: Frank Hodges' Link to the Ewings
McEwan: Origins of the MacEoghainn Clan: ...
McEwan: What can Y-DNA Tell Us ...?
McLaughlin: The Clan Ewing of Loch Lomond -- An Alternate View
Moore: A Y-Chromosome Signature of Hegemony in Gaelic Ireland
Spitler: Who Was James, Son of John of Carnashannagh?