Tarot cards are decks of cards used for divination (fortune-telling) and to evoke feelings and energy for Spirit and self. The basic rule is that each card represents a dimension or a hidden aspect of life and illuminates hidden subconscious issues by projecting onto the cards what you focus on subconsciously.
Hence, meditating on one particular card you can focus on until you feel a particular favorable outcome is attainable. This is called the short-cut method.
There are many decks available in tarot card deck markets but the deck or set you want should reflect your focus and intentions. When you are starting out, you can get a fairly decent deck without spending a lot of money. In some ways, these decks are more expensive than the mass market decks but many philosophers and sages of the ages have recommended them to their disciples, so they are worth the investment.
The cards should be placed face down or with the circle around them and should be separated from anything that may affect their read. The best is to have a set of very good cards without any problems, though some sleeves may friction against the cards and need to be smoothed down, but that is easily managed as well and just be aware of that for the reader's task.
Face down or with the circle of cards, they may be used to greetings, edification, prosperity, etc. The name of the Tarot by itself is just a form, not a meaning and the only identification you should go by is self, so use your own meaning most of the time. The neutral way (no meaning) is just a stepping stone to the more specific meaning that will serve you best.
When sending cards, never tell them to send a message about something that you want to happen or that you think they should. Always, you should be using the cards for exactly what is conveyed in the message. You want the cards to work as a purposed transmutation device to replace a negative force with a positive one or an energy that serves your intention and not the other way around.
As a Tarot reader, it is all about telling the story and none of it is ever a "truth" or "not truth" based, but more based on your intuition, and your reading, to me, is all about "messaging" a story to a seeker after Truth. Each individual has their own "self" or story, and the Tarot is just a symbol or tool that can help you to communicate your story to a person on the "other side".
Also, less is more when it comes to the use of the Tarot. No matter how elaborate our interpretation or how deeply we may dig, the cards should be asum of all the information available on the given cards, period. This may be a challenge for many readers, but many will go into a reading with the intent of gaining more information not only about their own life, but a person they have felt strongly about or a situation they have experienced.
This is great, practice, and fun, but also a great opportunity to practice and develop your intuition and subconscious mind. Trust your intuition and all will be revealed, including Tarot readings.