Missed this when you originally posted it. No books in English that cover the region specifically, and my guess would be that a generic hiking book would have little information on that region. The Villars/Gryon Tourist Office has a section on
Summer Hiking, the details include map, estimated hiking time, elevation gain/loss and GPS coordinates, complete with Google Earth track.
I would also buy the SwissTopo 1:50,000 map with hiking trails, 272 T St-Maurice. I suspect that when you actually get there you will find a locally produced map with a selection of hikes.