Tarot reading is a somewhat rigid form of magic in that it is pretty consistent in method and outcome. Tarot falls under divination.
Tarot refers to any of countless varying decks of cards.
Tarot decks should be handled with care and should be thoroughly cleansed every handful of readings to keep them from overflowing with conflicting energies. It is also suggested that a reader take part in a quick flushing of previously used energy before beginning each new reading, especially if the reading is for a different person than previously had. Some readers will thump the deck or use a crystal to absorb previously used energy. This may be followed by the person the reading will be focusing on holding the deck and focusing their own energy into the cards. This is commonly done by shuffling or visualization. From there, a question or topic is chosen by the person the reading is focused on. After that, cards are drawn at random and laid in order according to the spread chosen for the reading.
Tarot cards having individual meanings when placed respective to one another in what's called spread, are used for gathering bits of information depending on the question or topic for the spread at hand.
Spreads are the order and relative positions a number of cards picked at random are placed. Each spot has a significant meaning for the question or topic meant for that spread. Commonly each card will stand for a particular moment in time or the nature of the issue in question. Depending on the card, the spot it occupies in the spread, and where it's placed in relation to other cards multiple meanings can be interpreted from any one card.
Again, depending on the placement of cards they each mean something different.
Do not read each card in a spread directly from the book. This will jumble and confuse your reading and probably won't be too accurate. The booklets some decks come with are not supposed to be taken too seriously. They are generalizations that should really be looked at like suggestions or references to give you an idea about how tarot works. Many experienced readers will have several ways to interpret each individual card in their deck(s).