http://www.tightlinesflyshop.com/ind...on=Custom&ID=8
Check the hatch chart.
In May, in SWW, it's unlikely that you will see Little Black Stoneflies and Gray Drakes. Everything else is pretty reasonable.
Unless you're short on time, I'd probably take a pass on BEC. It's a hard little stream to begin with and get's relatively pounded being as close as it is to Madison, Milwaukee and Chicago.
Get a copy of Exploring Wisconsin Trout Streams by Born et. al., and a Gazeteer. That should set you up well enough for a small trip.