This is the new edition of Kraig's classic course on high magick of the western tradition. Here you will an excellent primer to get you going on the path particularly if you are interested in Golden Dawn Traditions and Thelema (although does not cover Thelemic rituals), although the course does contain a section detailing modern Wicca and Tantric material.
The new edition is much larger than the previous edition and includes some much better larger photos and diagrams, plus helpful summary sheets. New material is also inserted into the text at various points with Kraig's anecdotes, tips and updates on matters since the previous editions. At times these are insightful, witty and perhaps a little annoying but overall make for an updated better text than the original.
The New Chapter making this '12 lessons' includes Kraigs Synopsis of NLP, Chaos Magick and 'Post Modern Magick/Linguistics' ideas of Patrick Dunn. Personally, I found the section on NLP to be rather too brief to be of much value other than to just point the interested reader in the right direction. At a guess I might say there is 20% new material included in the book at the very most, comprised mostly of the new 12th chapter.
Overall an excellent buy, even if you have the old edition.