DuQuette's book is the best introduction for Hermetic qabalah by far, however, his focus is primarily on the Hebrew letters. If it is Hermetic qabalah you are interested in "The Kabbalah of the Golden Dawn" by Pat Zalewski is a magnificent read.
Barring these options, Q.B.L. by Frater Achad is a great introduction and one can see where DuQuette drew some of his inspiration, this can be found here:
The appendix is thought to be nonsense by most, but the rest is considered sound.
You also have Dion Fortune's in-depth classic, "The Mystical Qabalah" which can be found here:
And there is this video by Lon Milo Duquette which covers many of the concepts he has written about, however, the book is of course more indepth:
A kabbalah centre will most likely teach you jewish kabbalah which is more about the mystical interpretation of scripture. This is not the sort most magical practitioners get involved in because it is not practical knowledge really, more just theoretical. A good few books for this sort would be "The Bahir" and "Sepher Yetzirah" there are many translations but I prefer Aryeh Kaplan's. Then of course "The Zohar" but that is quite a read!