davmhl asks me to recommend some useful books on Magick, particularly of the logical/straightforward variety (citing Crowley's Magick in Theory and Practice (Book Four, Part III)). I'm gonna reply, but also take his suggestion to make it a thread-starter -- so please feel free to jump in with your own faves...particularly by answering the bolded question at bottom (or anything else you decide to reply with, natch). :D
I actually wrote (and self-publish) a book in which I attempt to boil the subject down to its essence: inward change (Mysticism), outward change (Magick) and the comprehensive balance of each with the rest of one's world (Thelema); hence its title: The C.'.G.'. Student Handbook: Mysticism, Magick, Thelema. The book analyzes the titles in Crowley's (short) A.'.A.'. syllabus, then devolves into a biographical sketch of AC, and a hint-a-thon on the nature of Thelemic attainment. So, y'know, that's the first one I'll recommend -- particularly since you already read MTP. (For those who haven't, the complete text is in Magick (Book Four, Parts I-IV) -- pricey but worth it, particularly in that it includes Part I, Mysticism, and Part II, Magick in its symbolic, psychological, initiatory senses.) Other important AC titles would have to include his letters to a student collection Magick Without Tears, and his Book of Thoth (on Tarot) and Eight Lectures on Yoga, IMO. And a final personal favorite: AC's The Heart of the Master (okay, and the essays "Duty" and (especially) "The Soul of the Desert," both in The Revival of Magick and other papers).
One problem with the field as a whole is that one can easily become lost in extravagant detail work with little practical effect: like studying ever more elaborate catalogs of bathing suits when what you really wanted was to learn how to swim. This isn't necessarily a bad thing; teachers absolutely have to learn all the fiddly bits so they can handle the needs of students (and the ceaseless snark of self-appointed teenage Ipsissimi of all ages), and bunches of this stuff has value simply because it makes you feel "magical" (as Grant Morrison so beautifully points out on his website). Big reason why I usually don't recommend titles: best that the inquirer follow out her or his own obsessions.
Still, the great danger of Magick has always been what I call "parking in Da'ath": one can become so obsessed with Knowledge Knowledge Knowledge, that he forever falls short of Understanding. AC's works (and mine, come to that) try to prevent this, which is the biggest reason I recommend 'em (yes, even my novels). I can't tell you how many people immerse themselves in Magick without ever quite managing to get at those three underlying purposes:
Changing oneself; changing one's world; bringing the two into harmony with one another.
I do, if asked, happily make recommendations for specific purposes. Want to know more about Qabalah? AC's 777, Godwin's Qabalistic Encyclopedia, and (if you can find a copy) Robert Wang's Qabalistic Tarot. Traditional medieval ceremonial? Aaron Leitch's Secrets of the Magickal Grimoires. Cutting-edge practical Magick? (other than my own books, natch ;) ): Phil Farber's FutureRitual, and I hope I hope he has more on the way; ditto for Grant Morrison's own promised handbook, if it ever materializes. Astrology: the works of Robert Hand, period. Mysticism, and fundamental world-changing: everything from the Lao-Tzu (Tao Te Ching) (particularly AC's own "initiated paraphrase" of same), to the Chuang-Tzu, the I Ching (use with caution!)...and even Sun-Tzu's Art of War. Thelema generally, Equinox III (10) leaps to mind; Thelemic attainment? AC's AHA! and Book of Lies. There! -- waaaay more than enough to start, and I've barely scratched the surface.
So, mighty F-list (if you're still reading this!), please reply as thou wilt, out of whatever tradition you like:
Which magico-mystical titles have had the greatest practical effect on you? -- in changing your life, changing your world, or helping you to perform your Will by bringing the two together in one harmonious whole?
93 93/93 -- AJ