My Mom gave me a book that might interest anyone looking into their South Wales ancestry:
"Pontyclun & Talygarn A History & Topography" written by J. Barry Davies, Trefor I. Rees, and M.A.K. Duggan Published by Llantrisant & District Local History Society.
The book includes family trees of some of the areas founders and prominent citizens as well as information on ownership and data collected from census info. Also, archived maps.