Blender 3D: Noob to Pro/Paths
It is fun putting a camera on a path and animating it through your scene. Just plop an old ordinary beizer curve into your scene and make it whatever shape you would like. Then put a camera in your scene and parent, CTRL+PKEY, it to the path. Select Follow Path from the menu that pops up. Then view your animation, ALT+AKEY. To set the number of frames it takes to get across the path, go to Editing (F9) panel for the path and set the number of frames in the PathLen, uh, thing with the arrows on the side and number in the middle.
Well, that should get you started. What I did for one scene, and what I recommend for all scenes, is to put an empty on another path and set the camera to TrackTo it via CTRL+TKEY TrackTo Constraint. It is tricky to get right but the results are rewarding.