well the switch on the camera also disables the switch on the lens and vise-versa, im just worried if I just switch the lens to manual focus and not the camera if I could mess up the cameras auto focus motor.
No, that can't happen. Before I explain why, here are the simple `rules':
(1) If the lens has an MF-AF switch, use that one. Not that using the switch on the body will cause any damage, but it's easier and in one location.
(2) If the lens does not have an MF-AF switch, use the one on the body.
That's it
Explanation:
If your lens has an AF switch and you switch it off, autofocussing is disabled and nothing can happen to the focus motor. Furthermore, I assume you have an AF-S lens (Nikon's equivalent of USM) which means that the focus motor is in the lens. The kit lenses have AF-S, so if you bought a kit, you're safe. AF-S lenses allow `instant override' which you are probably used to with your Canon, i. e. after using the AF, you can engage the focus ring and the camera will stop using the AF until you release the shutter and press it half-way again.
Second of all, even if you have another Nikon lens with an AF switch on it but with no built-in motor, the switch on the lens (which is then a mechanical switch) will decouple the focus screw in the lens (which connects to the focus motor in the camera body) from the focus mechanism. So again, once you engage MF on the lens, you're safe, nothing can happen.
The only time you
should be careful is when the lens does not have an AF switch: then you
must not work against the AF. Here, you must use the MF-AF switch on the body! There are also some third-party lenses (e. g. those from Tokina) which have an MF-AF switch (you slide the focus ring back and forth) which also then couples the focus ring directly to the mechanism. This is only relevant for some third-party lenses (gets increasingly less relevant for newer lenses), older, used lenses and old lens designs.
