Geraldine,
I highly recommend books/videos by John Howard Sanden. I have all of his books and all of his videos (just recently purchased his video of his copying of Sargent's "Lady Agnew").
His approach is very direct and very practical in my opinion.
His website is
www.JHSanden.com.
Many of his books/videos can be purchased off Ebay. There are usually items there daily.