Welcome, kmc,
First, the Mountaineers Route is in the Lottery if you day hike it, but if you want to do an overnight, the permits are reservable 6 months in advance, outside the lottery. They go fast.
As for maps: The Whitney Portal Store had a nice map of the main trail, but I don't think it shows the Mountaineers Route.
Here are two MR maps available on this site. The route on the map just below is a bit off-route.
Map_MR_RoutePrint.jpg (Try printing from your browser)
Map_MR_Route.doc A MS Word document
Here's a link to
MR information.