I have read somewhere that the H lenses do not work on D40/D0 bodies. Does that mean that metering and auto focus functions? Or these lenses cannot be mounted on these bodies at all?
Nikkor-H lenses can be mounted on the D40, but not the D90 without modification to the lens. Any attempt to mount a non-AI lens on the D90 can cause damage to the camera. Non-AI can be modified to AI by, among others, John White of AI Conversions for Nikon Lenses: Effective, Fast and Affordable! . After conversion, AI type lenses can be mounted on the D40/D90, but they will not auto-focus and will not meter.