FWIW, I will weigh in here, especially since I am a Thoth beginner.
So, in my opinion, Crowley's The Book of Thoth is well worth reading even for a beginner. Even though much of it will go flying over your (my) head, there is still so much worth reading in that book. I was warry at first, so I only ordered the DuQuette book when I ordered my deck. But I picked up the BOT in the bookstore and was just amazed by it. I loved it right away and bought it right away. On almost every page there was something that spoke to me, and amazed me. So even though I had no idea what a "Notariqon" was, or why zero=two was the supreme Thelemic doctrine, it was still well worth reading. You have to just let the feeling of being overwhelmed roll over you. You won't (and can't) understand everything all at once. It's a process. It takes time and work.
And the Thoth tarot is a great place to start, IMO. And DuQuette's book has been AWESOME for me, although it is not complete, I don't think.
He even says, at the end of Little bits you should know, something like "Now that we've discussed Qabalah and Astrology and Enochiana and . . . " and so on "we can move on to talk about the cards." BUT HE NEVER DISCUSSED ENOCHIA in part 1, nor did he say all that much about Astrology. This made me think that he was saying that you also needed to learn about Astrology and Enochiana in order to fully understand his card descriptions.
But, be that as it may, what I can say for sure is that the Ziggler (sp?) Mirror of the Soul book was, in my opinion, a complete waste of money.
So, hope that helps. I would say, beginner to beginner, that, yes, you want the BOT and DuQuette's book and you want to learn about Astrology.
Unless you just like the pictures on the Thoth cards and want to assign your own symbolism and meanings to them, in which case, definitely don't bother with any book, not even the LWB.