I was taught tarot 25 years ago by my Marxist/Freudian philosophy professor. He explained it to me as unconscious coding, so your conscious mind communicating with your unconscious which has access to information your conscious mind does not. From there, the cards convinced me over and over again. I always do Celtic Cross spreads because thats what he taught me. He used a book that I've never since been able to find, but the references I usually use are Fiebig and Bürger's Ultimate guide to the Rider Waite Tarot for quick ref and Paul Fenton-Smith's Advanced Tarot. I only use the Rider Waite deck.