If you use the Main camera, it's ridiculously simple - so much so that there's no need to script it.

Simply move your camera out to the distance from your object that you require (I'm assuming a circular camera path here). Make sure you have keyframed the first frame. If you're going for a looping animation (so it looks like the camera is continuously circling), then make sure you have the number of frames you desire in your animation plus one. You'll se why in a minute.

On the final frame, set the camera's y rotate to 360. If you play back this animation now, then your camera should move right round the object, as you desire. Now, move to the frame previous to the final one, and ad a keyframe to it without adjusting anything. Now delete that final frame - it's no longer required.

Render out this animation in the format of your choice, and play it back. You now have a looping animation of a continuously circling camera around your object. The reason we used the extra frame is because, if you simply set your final frame to 360, then when looping, you would get a minor stutter efffect because you have two frames at the same value (360 = 0). Be Using the extra frame and then deleting it, you make sure that the rate of change in the camera's position from the last fram to the first frame is the same as all the others, thus snuring a smooth transition in the loop.

Hope this helps.

JonTheCelt