There's no problem in using AF lenses on MF Nikon bodies as all AF lenses with the exception of the G series (see below) are AIS mount lenses.
One thing you'll find is that on the consumer AF lenses the focusing often feels loose and wobbly, this is due to the construction of the barrel. It's not a problem with the professional grade lenses though.
Nikon G series Lenses
Nikons G series lenses aren't fitted with an aperture ring to allow manual selection of aperture. This makes the lens incompatable with manual focus bodies such as the FM series, FE series, EM, FG and F3.