Is there an adapter/mount I can use to use my film lens (from my old Nikon 35mm camera) on my Nikon Dslr 3100? If so which one should I get? I have several Kiron lenses (made by Kino).
If, as I suspect, the lens is an AI or AI-S lens, then you should have no problem using it on your 3100. To determine if it is AI/-S, have a look at the aperture ring.
If you have two aperture scales (numbers going up in increments like 2.8, 3.5, 4, 5.6 etc), with the scale nearest the camera end of the lens in smaller type, you have an AI/S lens and it will work. This should be the case as I believe Kiron only made AI/S lenses for Nikon F-mounts.
Being an AI lens, you should be able to use it in Aperture and Shutter priority modes, but if this doesn't work you can put your camera in Manual mode to get the camera to take photos. It just means a little experimentation/practice with shutter speed in order to get a correct exposure, similar to when you're using a reversing ring.
Just in case, be very careful attaching the lens to the camera the first time, and if you encounter any resistance, don't force it, to avoid damaging the camera or lens.