I haven’t shot in the rain much, but when I did I cut the corner off of a gallon size zip lock bag. Then I stuck the lens thru the hole I cut and used a rubberband to hold the bag to the barrel of the lens. I then keep the zip lock part below the camera so the rain runs off it, and put my hand in so the camera and hand are inside the bag. If that makes any sense. I also keep my Guiness beer towel in my camera bag to wipe things off. As far as settings, I think that will depend on amount of light, amount of rain, equipment, etc. That is the good thing about digital, keep shooting and changing settings.
