My favorites are Magic Power Language Symbol by Patrick Dunn and The Philosophy of Natural Magic by Agrippa (can be found as a free ebook) that apply to any path. For specific paths I could possibly refer more depending on the path itself.
I would also recommend Parallel Myths by J.F. Bierlein since religion and the mythologies of them associate with magick.
I enjoyed Cunningham's Crystal, Gem, and Metal Magic although it is very basic, its a wonderful start for those who are beginning.
If you are interested in shamanism, be aware of "plastic shamans" (ones who claim they know things and are fake). For instance, with Cherokee practice Garrett (both of them) are the only authors I feel comfortable recommending.
For runes I prefer Thorsson and Aswynn as authors (all of their books).