Magick is the art and science of causing change, whether internal or external, in conformity with the Will. It is a field of study that touches virtually all aspects of existence. There is no ONE correct system of magick, as there are an infinite number of ways in which to accomplish any one thing. Reality is Infinite. All things are interconnected.
Beginners: if you're looking to learn the real essence behind developing serious skill in magick, then I highly suggest obtaining and working through Franz Bardon's text "Initiation Into Hermetics." (Don't skip anything!) Magick is a psychic skill that involves conscious use of energy/consciousness to cause change in conformity with the Will. You could consider that text the equivalent of psychic-weightlifting. It's not for the lazy. While I won't say that any one book will necessarily help anyone accomplish anything (since magick isn't learned solely from a book, it's learned through practice and hard work), that text at least points you into a 'real' and practical direction and shows you what the real work (the essence of it) is like behind all the glorified symbolism of most of today's convoluted ceremonial systems.
Elemental Energy: What it is and how to start working with it. Very basic primer geared toward the absolute beginner.
Basic Ritual Work: A brief discussion with sample rituals
Vibration of Names: Info on techniques of Vibration of Divine names for ceremonial magick and invocation.
Simple Exercises for Development: Some extremely simple exercises to assist in the development of the psychic abilities.
Astral Projection: What it is and some ideas on how to do it
Psychic Self-Defense: An Introduction
Elimination of Disturbances for the Inexperienced Beginner: Some simple methods to assist in the elimination of unwanted spiritual guests and psychic disturbances for those with little or no knowledge and experience in this area.
Miscellaneous Recommendations for Beginners: Random excerpts taken from emails and postings at occult forums.
Outline of a possible course of study: I wrote parts of this a few years ago in a Golden Dawn-ish style. If you're really stumped on how to make practical use of the info on this site then you can try this.
Initiation: Some thoughts on the topic for general info
The Kybalion: - Discusses Hermetic Philosophy in simple terms. This is a pdf version that was recently passed on to me. This text is in the public domain, so I can legally pass it on to you. Requires Adobe Acrobat Reader to view it.