Winter Care of Rhododendron

I have two Rhododendron plants I need to get ready for winter. I know that I have to cover them for winter but do I need to cut the plants back before doing that? If so, how far back?

Your rhododendrons have already formed their flower buds for next spring. Do not prune these until after they bloom next spring. And only prune after flowering if you need to shape or control the size of these plants. Shelter these and other broadleaf or sensitive evergreens from the winter wind and sun. Use a screen of burlap or lattice or a cylinder of hardware cloth sunk into the ground and then filled with evergreen boughs or straw after the ground freezes.