I just finished " The Weiser concise guide to Aleister Crowley" Awesome book. here is a blurb:

Author Richard Kaczynski's guide offers Crowleys teaching in his own words with a carefully chosen series of instructions for concentration, meditation, magick, Invocations, even sex magick. Crowleys descriptions of the teaching Orders A*A*, and OTO are presented, along with the Creed of EGC. This is the first and only introductory book that does not pretend to improve upon the Masters writing, but attempts to showcase them into a coherent introduction to his spiritual system.