for warm rain usually just a rain jacket, nothign fancy.
cold rain, the same rain jacket, with more layers underneath...
I usually wear the plastic baggies from the grocery store over my socks when riding through rain to keep the feets dry. A rubberband at the top of my sock keeps all but a little rain out. I find that as long as my trrunk stays dry I am okay. it doesnt get all that cold here in south Texas.