Wicca for the Solitary Practitioner, Scott Cuningham - A well-known and well respected book for beginning Neo-Wiccans (non-initiated path), and helpful to others who are curious about Wicca.
Sabbats, Edain McCoy - If you can gloss over her historical mistakes, the projects, recipes and descriptions she gives for each holiday can be enriching.
Advanced Witchcraft, Edain McCoy - One style of working magick on a long-term or in-depth basis.
Pagans and the Law, Dana Eilers - A primer on your rights, responsibilities and how the legal system works in reguards to the religious clauses of the 1st amendment.
Drawing Down the Moon, Margot Adler - A worthwhile history of American Neo-Pagan paths and inflences.
Secret Language of Symbols, David Fontana - A well-illustrated and helpful book on some occult and popular symbolism.
Magic and Medicine of Plants, Readers Digest - I love this book. Period. Just read the description on the site and you'll see why.
Prescriptions for Nutritional Healing and Prescriptions for Herbal Healing, The Balches - Two good volumes for in-depth nutritional and herbal healing. Find suppliments, herbal remedies and various techniques for aiding a wide variety of ailments. A necessity for anyone in the business of healing.
Getting out there:
Petersons guides - One of the most well-known types of natural guides to perpare you for and help you identify whats out there when you're in the wild... or even in your backyard.
The SAS Survival Handbook, John Wiseman - A useful book for learning how to deal with survival situations.
Born Survivor, Bear Grylls - Another useful survival book with an attitude of reverence and an understanding of the human animal.