There aren't any reversals with regular playing cards as they are the same both ways. It is possible to mark them so that you have the chance of reversed cards showing up.
Reversed cards can mean the opposite, but they are more likely to show that the energy of the upright meaning is weakened or 'malformed'.
So taking the Ace of Hearts as an example, it could mean that a new friendship doesn't get going properly, or that the 'friend' isn't really a friend, or the new romance is dead in the water. As always, context is everything.
Personally I rarely read with reversals, even with tarot cards, as I think that all the meanings are available in the upright cards. It's all in there, and if my intuition whispers that the card's negative aspects are more suited to the interpretation, then that's what I go with.