Subbie's right. The key is the center.
The image shows that the top color must be yellow.
There are a few techniques for solving the cube, but since the center cross is the stationary piece of the cube, and the faces move around
it, it is that center cross, and the squares connected to it, that determine where each color will be: the same cube will always have the same colors in the same positions relative to one another when solved.
The method I use involves solving a single face and then solving 'down' the cube until you get to solving the face opposite the starting one. But that is a slower method, and I've never gone faster than about one minute.
Google it and you will see how it's done
There are also tips on doing the faster methods; they take more thought, so I've never bothered with them.
Love your enemies!