In hearts, the object is either to take all the hearts (which gives each of the other player 26 points), or to take none of them. Those are ideals, and usually, you're doing well if you take as few hearts as possible. The "Bitch," the Queen of Spades, is worth 13 points, and each heart is worth one point. As soon as one player gets over 69 points, or 100 points (it varies regionally), the game is over and the player with the lowest score has won.
Spades, however, is a pretty standard trick-taking game, but spades are always the trump suit.