That would depend on what you are wanting to know.
If it is just basic I like the three card representing past, present, and future or the five card spread representing the same but with two transition cards in between.
They are basic but work well for me. There are all kinds. It is just a matter of finding one that works for you and having the right deck also helps, if you don't really like the deck then your negative energy will effect the outcome too. Researching all the spreads and decks never hurts, only helps. :)
It also depends on the spell that was cast.
You can ask them yes and know questions. I read them like this: if the card laid is in the normal position it means yes, if upside down it means no, but always check the mean of the card in the position it is in, it maybe trying to tell you something.
Hope this helps and Blessed Be