The Age of the Earth
G. Brent Dalrymple
Stanford University Press, Stanford, CA (1991)
474 pages including index
ISBN 0-8047-1569-6
Library of Congress catalog number QE508/D28

An excellent and in-depth summary of the major dating methods, not
difficult to read (although knowledge of algebra and chemistry helps).
Extensive references (35 pages), very good glossary and index.

The focus is on the Earth, so most of the book is concerned with
radiometric and chemical dating of rocks, including whole chapters
on the results from lunar and meteoric rocks.  He does include a
chapter on earlier estimates (Biblical, cooling of Earth and Sun,
salt and sediment clocks, etc.) as well as on the dating of the
universe (Hubble measures, Hertzsprung-Russell statistics, element
and isotope abundances, etc.).

If nothing else, worth it for the references.  For example, you can
now refer to Ussher's work using the correct title, viz:

      The Annals of the World.  Deduced from the origin of time,
      and continued to the beginning of the Emperour Vespasian's
      reign, and the totall destruction and abolition of the temple
      and commonwealth of the Jews.  Containing the historie of
      the Old and New Testament, with that of the Macchabees.
      Also all the most memorable affairs of Asia and Egypt, and
      the rise of the empire of the Roman caesars, under C. Julius,
      and Octavianus.  Collected from all history, as well sacred,
      as prophane and methodically digested by the Most Reverend
      James Ussher, Archbishop of Armagh, and Primate of Ireland.