Hi Terry,
Here's a link to quite a good book on the subject.
http://freebookspot.org/TopTen.aspx?Category_ID=96
Just scroll down and you'll find.....
"Spectroscopy: The Key to the Stars: Reading the Lines in Stellar Spectra"
You can download the book as a .pdf, and if you like it go buy the hardcopy.
Hope you find it useful.