Aperture ring

The Nikon lens that I am using does not have an aperture ring. Is that going to hinder the functioning of my camera-D90?

No it will not. In manual or aperture priority mode you set the aperture using the camera's controls, not the aperture ring.

using the aperture ring on a lens with the D90 will cause the EE error, if you have a lens with a manual aperture ring lock it down at it's smallest setting (highest F number)