Reddit reviews Tarot Theory and Practice: A Revolutionary Approach to How the Tarot Works

I recommend this with the caveat that I have entirely discarded chunks of it:
Tarot: Theory and Practice by Ly de Angeles

I don't use any of her Kabbalah-based theory, but I take a lot of her practical advice, and she has some good things to say on the ethics of reading for other people. Also, she tends to take kind of a condescending witchier-than-thou tone, though it's not as bad here as some of her other books.

I also really love Noxporium. Link to the stop card page because I think it's a useful tool that not enough people have heard of.

And who would I be if I didn't plug Rune Soup, my single favorite magic blog ever? Gordon has some good entries on using multiple decks, calibrating them, etc--just put Tarot on the search bar.