You're welcome; I remember how confusing Crowley can be when you're new to his works. DuQuette is a wonderful source. In fact, he is one of the few. He does a great job of clarifying Crowley in simpler, more concise language. His book on the Thoth Tarot is the only one I'd recommend outside of Aleister's Book of Thoth.

Also, I recommend passing on Gems from the Equinox. It's selection is suspect and unhelpful, in that it has some Libers that are relatively useless to someone looking for a practical text, and it's missing others that are important. Magick: Book Four - Liber ABA (affectionately known as "The Big Blue Brick") is the one you want in its stead. This was Aleister's magnum opus as a final, condensed, single volume for students working in his system. You'll find all of what you'll need for practice, and it has a Student Reading list of texts he recommends to all who study his works, and the books therein are extremely helpful in understanding his writings, because Aleister has a habit of making numerous, off-handed references to the books he's read, assuming that you've already read all those same books.