This is a link to a PDF Document called...
A Gentle Introduction to Genetic Genealogy, by David A. Pike.
Through easy-to-understand examples, it puts in simple language how yDNA (paternal) and mtDNA (maternal) testing can help genealogists with their Family Research. Included within his article, Mr. Pike gives the reader an overview of DNA testing, examples of how to use your results and ideas for getting started with Genetic Genealogy. This well written article is a must for genealogists new to this type of research.