Actually that could be a rather long explanation depending on what it is that you're trying to do. A simple "camera following a path" setup would be to create a 'camera and aim', draw a curve to be your path, create 2 locators, parent the camera to one of them (lets say thats locator 1), and point contrain/or parent the camera's aim to the other(locator 2). You can see all this in the Outliner window, when you're done with the parenting you can just drop all that stuff back under the camera group if the group gets all broken up. Select locator 1 and then select the curve, go to Animate>Motion Paths>Attach to motion path. You may need to tweak the attributes. Locator 2 is what you use to aim the camera, you can animate this or get crazy and attach that to a motion path too /shrug. If you're going to get into all that I suggest you check out making a 'camera aim and up' and check into how that and keying motion paths and just generally how they work.