the three well-known books on the de Graffenried family are:
de Graffenried, Thomas P., 1925, History of the de Graffenried Family--1191 AD to 1925:Vail-Ballou Press, Binghamton and New York, 282 p.
de Graffenried, Thomas P., 1950, The de Graffenried Name in Literature: The William-Frederick Press, New York, 32 p.
de Graffenried, Thomas P., 1958, The de Graffenried Family Scrap Book 1191--1956: University of Virginia Press, Charlottesville, 270 p.
You will also see references to a large collection of data on Baker DeG., the first surviving son of Tscharner [Tscharner, born in America, is the grandson of Christoph, the Swiss "Baron" (Landgrave) who founded New Bern, NC in 1710; Tscharner's father was also Christopher v. Graffenried, born in Switzerland, died in America]. This reference is:
Reynolds, Katherine, 1962, Descendants of Baker and Sarah Vass De Graffenried, Virginia and North Carolina:Submitted to Samuel Sorrell Chapter, NSDAR, Houston, Texas, Vol. I, 463 p., Vol. II, 341 p.
There is also a much-quoted book by Todd:
Todd, Vincent H. (ed.), 1920, Christoph von Graffenried's Account of the Founding of New Bern:North Carolina Historical Commission, Edwards & Broughton, Raleigh, N.C., 434 p.
Betty Wood Thomas, director of the de Graffenried Association in San Antonio (search WWW for deGraffenried.com -- I don't recall if there's a space between de and G) has been working to update Thomas P. de Graffenried's 1925 History for some years and I understand it's in final proofing. There are connections at this site to archives of DeG. material at a NC university and I think the NC historical society, as well. Some of the DeG. literature is available at these links.