Part of a writer's line of work is research, otherwise the story falls flat (even pure fantasy need some sort of research, like weapons or whatever)....so what about good research resources?

Like me currently I am trying to find good resources (online preferably) of the effects of nuclear fall out. I have a general idea what happens to the human body....but not exact...also the effects on the environment...and the spread of the fallout.from hot zones...to more remote areas... Like I said I am looking..and have found some ok sources...but nothing that goes into detail.