I would like find a class to manipulate the camera...

Now, I’m trying to make a class about the camera…where it is possible to fix the position of the camera source and the target, to rotate the camera with a variable angle around the axe x, y or z…But, the rotation it is not perfect ! Objets rotates but in the bad direction. In return, the position (x,y,z) of the camera and this target are good!(after calcul and drawing on paper). Other question, the axe Z corresponds to the top of the repere. (excuse me for faults, I’m french…)