Real boards and battens wouldn't be nearly as good on your shed as plywood. No structural shear resistance, joints leak water when battens swell/when wet from rain, not air-tight or bug-tight as plywood can be. Rough sawn plywood, smooth face- T1-11 is called 303 siding, since I used it in the late '70's.
http://www.apawood.org/plywood
It comes without the grooves, correctly mentioned already- in post above. Way faster on installation, hardly any water intake (unlike real boards) due to the exterior type glue layers. With only a thin outer plywood layer before the first waterproof glue layer, it would dry out way faster than a real board 3/4" thick (usually cedar) which gets the whole thickness wet. Add some solar gain after a good rain and the moisture is driven into the shed/contents when the surface paint breaks down. I've installed both, for years and the plywood base is far superior to individual boards and looks the same, if not better.
You don't need a grooved (stucco type) WRB with the panels, just builders paper is fine. The grooved housewrap doesn't do much to help dry from the backside;
"The air space created by these products is minimal, ranging from 0.02 inch thick for StuccoWrap to 0.008 for RainDrop®. Although these materials may allow for some drainage, it is unlikely that they will provide any measurable airflow to promote drying.
A more promising approach is a 1/4-inch nylon matrix, called HomeSlicker®, which has vertical drainage channels and installs between the sheathing wrap and siding. The material is rigid and thick enough to resist compression by the siding but thin enough that windows, doors, and trim can be installed without furring." -------also read up on builders paper here;
http://inspectapedia.com/BestPractices/Sheathing_Wrap_Requirements.php
Gary
