I've done similar shelf installation down and dirty with lag screws into the studs. Once driven, the heads were cut off, and holes bore in the back of the shelves with an auger bit. Squirt some PL adhesive in the holes and slide it on.
Jason Holtz J. Holtz Furniture
3307 Snelling Ave. South
Minneapolis, MN 55406 612 432-2765
-- Jason J. Holtz Furniture 3307 Snelling Ave. South Minneapolis, MN 55406