From an individual student's point of view, the most complete
allegorical (
is that the word?) explanation of Kabbalah that
Crowley wrote. A lot of the other things he put onto paper were motivations, applications, desires and needs as far as magick is concerned, but this is a map. Actually, the
chapter that is not a chapter is probably the most concise explanation of Kabbalalistic creation I've ever heard.
As a side note, a lot of this stuff is crazy, very very hard to understand, but if you're interested in Crowley please read The Book of the Law, 4, and 777. As a huge help in understanding Crowley and the Western Mystic Tradition altogether please read anything by Lon Milo DuQuette.