Charcoal Papers are any light colored papers with a slight tooth or texture. Charcoal papers can be used as well with pastels, pencils, and other drawing media where a textured surface is desirable.
Dick Blick offers a wide selection of Pastel Papers and Surfaces. Any light colored pastel paper can be used for charcoal drawing.
See Drawing Papers and Surfaces for a selection of papers suitable for all media, including several that are available in bulk for classroom use.