I've been reading Tarot for over 10 years now.  At one time I used the Witches Tarot.  It is a very beautiful deck.  However, they are somewhat limiting in the info they show.  The Ryder-Waite deck has the most symbols, which can help the reader to see the meanings and it's one of the easiest to learn Tarot with.  It's also the deck used by the MB software.  

The bottom line is it's up to the individual as to which deck they want to use.  I do suggest, however, if you get any deck that you also get the book that accompanies that particular deck, for the reason that the definitions in that book will help to see the meanings of the particular cards in that deck.  But you can also get just about any book to teach you to read Tarot that you want, but the meanings from a book other than the book accompanying the deck will be different at least somewhat.

Hope this helps,

MySpirit1111

The theory is that the cards, like any other object, has a mind of its own and will disappear sometimes and then reappear when needed.

In the above scenerio where the cards didn't belong to that person, but were loaned and not returned, some people would say that's bad Karma being created by stealing the deck or at least not returning it.  

I feel a person can learn Tarot with any deck and under any circumstance.  But I also feel it's easier to learn if you start out with your very own deck and get your own energy into that deck, more or less become one with the deck.

Hope this helps,

MySpirit1111