And if you don't have a rain garden built yet, here are some plants for wet areas in your garden:
Arrowwood viburnum shrubs
Swamp milkweed, which is a good butterfly plant
Elephant ear plants--this is a tropical plant and is the only one that will not survive in lower zones.
Here in Louisiana our swamps are full of marsh marigolds. I think they are a cousin of hibiscus or mallow because flowers look the same. Louisianians call them marshmallows. Doncha love it?
I have my rain garden planted and it is filling in slowly. Be sure, when you remove the sod, you remove it all. I didn't do a great job, so spent several hours on my hands and knees, sinking into some pretty stinky water getting the rest of the grass out.