Holistic Tarot by Benebell Wen is magisterial, immensely informative, does not have a proficiency bias, and the supplementary learning documents in her website are just astounding. You really cannot fault her book with anything, except that it has an RWS slant.
I would also very highly recommend Tarot Wisdom by Rachel Pollack. Dense with info, immensely helpful, and easily understandable, it features a handful of the major decks, so it is not biased towards a specific one.
If you're into esotericism like the Qabala, Sheshamphoresh angels, astrological and other attributions, etc., The Qabalistic Tarot by Robert Wang would be very useful to you, featuring as it does the Golden Dawn, Thoth, RWS, and Marseilles Tarot decks. By its pretty complex nature though, the Qabala may require a separate introductory book, although in this one the author did try to make that as simple, straightforward, and beginner-friendly as he can.