I've been reading tarot for over 20 years and I own 115 tarot decks. So far. Tarot isn't going to tell you something you don't know, but it can and frequently does show you things in ways you hadn't thought of. I would never make a decision based only on a tarot reading but I do use it as a tool to contribute to making a decision.
I've read for skeptics a number of times. All of whom turned less skeptical by the time the reading was done.
I have a beutiful witch friend, she really knows how read this cards, and she told me things than really has happened in my life, but warning! (just like ouija) if you do this with the wrong person or somebody without experience, could be dangerous, so my advice is you don't try!