Initiation Into Hermetics - Franz Bardon. Get this book. Full of hands-on practical exercises that you won't find anywhere else. His 'system' of work isn't for the lazy. This text will help you learn the essence of psychic/magick work - primarily without rituals. If you could only own one book on magick, then you wouldn't go wrong with this one.
These books, when used together, should provide a good foundation for general self-defence.
Practical Psychic Self-Defense: Understanding and Surviving Unseen Influences - by Robert Bruce
This is one of the best books I've seen on the topic! Some of his techniques are very simple but effective for most average disturbances, and he doesn't waste time with anything that isn't practical or proven effective through his own systematic trial and error. BUY THIS BOOK!
Way of Psychic Protection - Judy Hall (2001)
A pretty good book actually. When first reading it, I felt that she was too new-agey. However, upon closer inspection, I see that she actually has some very good information in here. I must say that, although I was skeptical about using Flower Essences, after trying them out myself and witnessing some interesting energy effects, I now must conclude that they WORK. She also talks a bit about use and misuse of energy links.
The Art of Psychic Protection - Judy Hall - this might actually be the same text through a different publisher. Appears to have fewer pages than the one above though and is dated 1997.
Practical Guide to Psychic Self-Defense and Well-Being - by Melita Denning & Osborne Phillips.
From what I've seen of these authors in their other books on magick and the occult, they're serious and their information is founded upon authentic occult techniques.
Psychic Self Defense- Dion Fortune. A good beginning text on a very important aspect of magickal study. Regardless of her biases at the time that she wrote the text, the essence of what she has to say is worth the small amount of money you'll spend on this book.
Hands of Light : A Guide to Healing Through the Human Energy Field- Barbara Ann Brennan. A very good book on working with energy as well as healing oneself and others. Written by a former physicist who happened to be a natural clairvoyant. Highly recommended. This book is often used by serious alternative medical schools.
Light Emerging : The Journey of Personal Healing- Barbara Ann Brennan. Another interesting read from the same author. She's a bit new-agey and almost 'christian' at times, but the information in her texts is still very useful.
Frans' books here...
Astral Dynamics: A New Approach to Out-of-Body Experiences by Robert Bruce -
Don't you love it when you pick up a book that immediately explains experiences you've had but had no explanation for when they occurred? This doesn't happen often, but it might with Astral Dynamics, Robert Bruce's straightforward how-to manual on astral projection. Perhaps you've had a spontaneous out-of-body experiences and didn't know it! This extensive tome teaches you everything you need to know to accomplish successful, planned out-of-body travel; how to exit the body, how to get around on the astral plane, and how to get back in with solid, provable memories of the event. Bruce writes very clearly and uses down-to-earth terminology so that you learn not only how to create a "real-time double" to astrally project but also about the physics of the nonphysical world. Out-of-body experiences can be so confusing that enjoying them or employing them usefully can be a serious challenge. Fortunately, Bruce now brings his 25 years of interdimensional experience to the aid of astral explorers the world over, and everywhere else too. --P. Randall Cohan"