hmm… for some reason my last post didn’t come through… (sorry for the double up if it does!)
The MouseLook.py script is one from www.tutorialsforblender3d.com, it is best to save this as a text file and use it when needed - what to look for is the way the logic bricks are set up.
You’ll see that the UpDown actuator is tied to the camera, so when the mouse pitch changes the script rotates the camera up and down (oh, the logic bricks must be called as they are, since the script is looking for those names).
The LeftRight actuator is tied to player cube and rotates it according to the mouse movement. The camera is parented to the player cube, so when the player moves, so does the camera.